ARTICLE | doi:10.20944/preprints202211.0370.v1
Subject: Chemistry, Food Chemistry Keywords: hen egg white lysozyme; chemical modification; antibacterial activity; secondary structure
Online: 21 November 2022 (04:40:14 CET)
Egg white lysozyme was modified by chemical methods using organic acids. Caffeic acid and p-coumaric acid in organic acids were used as modifiers, and 1-Ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxy succinimide were used as dehydration condensation agents during modification. A certain degree of modified lysozyme was obtained through appropriate modification conditions. The antibacterial properties and structure of the obtained two organic acid modified lysozymes were compared with natural enzymes. The results showed that compared with the natural enzyme, the activity of modified lysozyme decreased, but the inhibitory effect on Gram-negative bacteria was enhanced. The minimum inhibitory concentrations of caffeic acid modified enzyme and p-coumaric acid modified enzyme on Escherichia coli and Pseudomonas aeruginosa were 0.5 mg/mL and 0.75 mg/mL, respectively. However, the antibacterial ability of modified lysozyme to Gram-positive bacteria was lower than that of natural enzyme. The minimum inhibitory concentration of caffeic acid modified enzyme and p-coumaric acid modified enzyme to Staphylococcus aureus and Bacillus subtilis was 1.25 mg/mL. The peak fitting results of the amide-I band (1600 cm-1-1700 cm-1) absorption peak in the infrared spectroscopy showed that the content of the secondary structure of the two modified enzymes obtained after modification was different from that of natural enzymes.
ARTICLE | doi:10.20944/preprints202211.0253.v1
Subject: Chemistry, Food Chemistry Keywords: Low-field NMR; Two-dimensional nuclear magnetic resonance; Edible oil; Chain length; rotation correlation time
Online: 14 November 2022 (10:51:18 CET)
Nuclear magnetic resonance (NMR) techniques are widely used to identify pure substances and probe protein dynamics. Edible oil is a complex mixture composed of hydrocarbons, which have a wide range of molecular size distribution. In this research, low field NMR (LF-NMR) relaxation characteristic data of various sample oils were analyzed. We also suggest a new method for prediction size of edible oil molecules using LF-NMR relaxation time distributions. According to the relative molecular mass, carbon chain length, transverse relaxation time of different sample oils, combined with oil viscosity and other factors, the relationship between carbon chain length and transverse relaxation time rate was analyzed. Various oils and fats in the mixed fluid are displayed, reflecting the composition information of different oils. To study the correlation between the rotation correlation time and molecular information of oil molecules. The molecular composition of the resulting fluid determines its properties, such as viscosity and phase behavior. The results show that low-field NMR can obtain information on the composition, macromolecular aggregation, and molecular dynamics of complex fluids. Measurements of grease in the free fluid state show that the relaxation time can reflect the intrinsic properties of the fluid. It is shown that the composition characteristics and states of complex fluids can be measured by low-field nuclear magnetic resonance.
ARTICLE | doi:10.20944/preprints202209.0405.v1
Subject: Chemistry, Food Chemistry Keywords: deep frying; olive oil; sesame oil; sesame lignans; Total Polar Compounds
Online: 27 September 2022 (03:11:31 CEST)
Fresh potatoes were deep-fried in olive oil (OO) & extra virgin olive oil (EVOO) and their blends with 5%, 10% and 20% v/v sesame oil (SO). This is the first report on the use of sesame oil as natural source of antioxidant for olive oil deep-frying. Oil was evaluated for Peroxide Value (PV), Free Fatty Acids (FFA), K232, K270, Trolox Equivalent Antioxidant Capacity (TEAC) and Total Phenols (TP) until Total Polar Compounds (TPCs) reached 25%. Sesame lignan transformations were monitored through Reverse-phase HPLC. While TPCs in olive oils increased at a steady rate, the addition of 5%, 10% and 20% v/v SO created a time window lasting 1, 2 and 3 hours, respectively, where TPCs were constant. SO addition to OO increased the total frying time. Furthermore, the addition of SO reduced the peroxides formation rate for both OO and EVOO. EVOO was more resistant to oxidation than OO as measured by TPCs and TEAC, while frying time raised from 21.5 to 25.25 h when EVOO replaced OO. The increase in frying time for olive oil but not for extra virgin olive oil, after SO addition, is pointing out a niche market for extra virgin olive oil in deep-frying.
ARTICLE | doi:10.20944/preprints202209.0384.v1
Subject: Chemistry, Food Chemistry Keywords: prebiotics; resistant starch; inulin; polydextrose; farinography; extensography
Online: 26 September 2022 (08:32:33 CEST)
The addition of prebiotics is one of the most important ways to improve the techno-functional properties of bread. In this study, the effects of resistant starch, polydextrose, and inulin on the wheat flour, dough, and bread properties were investigated. In farinography results, resistant starch significantly increased the development time (2:18) with a boosting effect, but polydextrose (1:48) and inulin (1:36) weakened the dough (P <0.05). Inulin, polydextrose, and resistant starch had the most effect on reducing water absorption (40, 43.2, and 48.9) respectively (P <0.05). According to extensography data, inulin had the best result in baking compared to other polysaccharides. In terms of baked breads, samples containing resistant starch had high moisture that could be due to starch gelatinization and moisture-retaining, which delays the staling process of bread. Inulin, polydextrose, and resistant starch prebiotic ingredients affected dough rheological properties and bread quality, and organoleptic characteristics, however, resistant starch was the best.
REVIEW | doi:10.20944/preprints202209.0183.v1
Subject: Chemistry, Food Chemistry Keywords: hexane; toxicity; 2,5-hexanedione; food industry; alternative extraction methods
Online: 14 September 2022 (02:36:04 CEST)
Hexane is a solvent used extensively in the food industry for the extraction of various products such as vegetable oils, fats, flavours, fragrances, colour additives or other bioactive ingredients. As it is classified as a "processing aid", it does not have to be declared on the label under current legislation. Therefore, although traces of hexane may be found in final products, especially in processed products, its presence is not known to consumers. However, hexane, and in particular the n-hexane isomer, has been shown to be neurotoxic to humans and has even been listed as a cause of occupational diseases in several European countries since the 1970s. In order to support the European strategy for a toxic-free environment (and toxic-free food), it seemed important to collect scientific information on this substance by reviewing the available literature. This review contains valuable information on the nature and origin of the solvent hexane, its applications in the food industry, its toxicological evaluation and possible alternatives for the extraction of natural products. Numerous publications have investigated the toxicity of hexane, and several studies have demonstrated the presence of its toxic metabolite 2,5-hexanedione (2,5-HD) in the urine of the general, non-occupationally exposed population. Surprisingly, a tolerable daily intake (TDI) has apparently never been established by any food safety authority. Since hexane residues are undoubtedly found in various foods, it seems more than necessary to clearly assess the risks associated with this hidden exposure. A clear indication on food packaging and better information on the toxicity of hexane could encourage industry to switch towards one of the numerous other alternative extraction methods already developed.
ARTICLE | doi:10.20944/preprints202207.0340.v1
Subject: Chemistry, Food Chemistry Keywords: dietary plants; medicinal plants; extraction; solvent; phytoconstituents; antioxidants; anti-nutrients; radical scavenging
Online: 22 July 2022 (13:16:10 CEST)
Sesamum indicum is considered an underutilized oil-bearing seed in the semi-arid regions of Ghana. Nonetheless, it is a promising source of food with both nutritional and therapeutic benefits. The aim of the present study was to evaluate the antioxidant properties S. indicum seeds using different extraction solvents. The seeds were obtained from the local farmers and prepared for analysis. The bioactive compounds present in the seeds were extracted using hexane, ethyl acetate, ethanol and water and their yields quantified. Total phenolic content (TPC), Condensed tannin content (TTC) and Total antioxidant capacity (TAC) , and DPPH radical scaveging assay were analyzed using standard methods. Antinutrients such as saponins, alkaloids, phytates and oxalates were also analyzed from the powdered seeds. Two chemometric methods; hierarchical cluster analysis (HCA) and Pearson correlation were employed to evaluate the interdependence of the various parameters to result in their antioxidant properties. The re-sults revealed that the solvents utilized had a significant impact on the extraction yield, phyto-chemical component concentration, and antioxidant activities. Hexane extracts of S. indicum seeds significantly exhibited the highest antioxidant activity (p < 0.05). It was marked with the highest TAC value of 232.6 ± 6.267 mg/g AAE and a strong DPPH scavenging activity with an IC50 of 52.81 ± 2.30 µg/mL. Correlations (p < 0.05) was established between TPC,CTC, TAC and DPPH radical scavenging activity) of the extracts. Antinutrients such as; phytate, oxalate, saponins and alkaloids were found to be 7.691 ± 0.8576, 1.501 ± 0.1375, 21.33 ± 4.619 and 317.33 ± 30.29 mg/g respectively. Data obtained suggest that S. indicum possess rich bioactive compounds that can be used in neutraceuticals and food products.
ARTICLE | doi:10.20944/preprints202207.0087.v1
Subject: Chemistry, Food Chemistry Keywords: millet porridge; electric cooker; nutritional composition; principal component analysis; cluster analysis
Online: 6 July 2022 (04:38:57 CEST)
(1) Background: In order to study the effects of different electric cookers on the nutritional components of millet porridge, five different electric cookers were selected to cook millet porridge, and sensory and nutritional components in millet porridge, millet soup, and millet grains were analyzed. (2) Methods: Using principal component and cluster analysis, a variety of nutritional components were comprehensively compared. (3) Results: The results showed that among the different cooked samples, the content of amylose and reducing sugar was the highest in the samples cooked by electric cooker no. 3. The electric cooker no. 4 samples had the highest sensory evaluation score, crude fat, and protein content. The contents of ash, fatty acids, bound amino acids, and minerals were the highest in the electric cooker no. 5 samples. The sensory evaluation score and content of crude fat, ash, reducing sugar, direct starch, and Cu were higher in millet grains than in millet soup or porridge. The content of fatty acid, protein, amino acid, Zn, Fe, Mg, Mn, and Ca was highest in millet soup. Different electric cookers produced millet porridge with varying nutritional levels. (4) Conclusions: This study provides a reference for the further development of new electric cookers.
ARTICLE | doi:10.20944/preprints202206.0321.v1
Subject: Chemistry, Food Chemistry Keywords: coffee leaf tea; novel food; coffee by-products; Coffea arabica; caffeine; epigallocatechin gallate
Online: 23 June 2022 (09:22:46 CEST)
The production of coffee leaf tea (Coffea arabica) in El Salvador and the influences of processing steps on non-volatile compounds and volatile aroma-active compounds were investigated. The tea was produced according to process steps of conventional tea (Camellia sinensis) with available possibilities on the farm. Influencing factors were the leaf type (old, young, yellow, shoots), processing (blending, cutting, rolling, freezing, steaming), drying (sun drying, oven drying, roasting) and fermentation (wild, yeast, Lactobacillus). Subsequently, the samples were analysed for the maximum levels of caffeine, chlorogenic acid, and epigallocatechin gallate permitted by the European Commission. The caffeine content varied between 0.37 g/100 g dry mass (DM) and 1.33 g/100 g DM, the chlorogenic acid between not detectable and 9.35 g /100 g DM and epigallocatechin gallate could not be detected at all. Furthermore, water content, essential oil, ash content, total polyphenols, total catechins, organic acids, and trigonelline were determined. Gas chromatography—mass spectrometry-olfactometry and calculating of the odour activity values (OAVs) were carried out to determine the main aroma-active compounds, which are β-ionone (honey-like, OAV 132-927), decanal (citrus-like, floral, OAV 14-301), α-ionone (floral, OAV 30-100), (E,Z)-2,6-nonadienal (cucumber-like, OAV 18-256), 2,4-nonadienal (melon-like, OAV 2-18), octanal (fruity, OAV 7-23), (E)-2 nonenal (citrus-like, OAV 1-11), hexanal (grassy, OAV 1-10), and 4-heptenal (green, OAV 1-9).
ARTICLE | doi:10.20944/preprints202205.0012.v1
Subject: Chemistry, Food Chemistry Keywords: Flammulina velutipes; fermentation broth; umami taste; nutrients; electronic tongue; mushroom byproducts
Online: 4 May 2022 (14:14:18 CEST)
As one of the most appealing edible mushrooms, the quality of Flammulina velutipes can be affected by the cultivation substrate, which has an impact on the mushroom umami taste and nutrients. In our study, the effect of mushroom root fermentation broth (MRFB) based substrate on umami taste and nutrients of F. velutipes were evaluated; four proportions of MRFB was conducted (CK 0%, E1 6.7%, E2 13.4%, E3 20.1%). Results indicated that MRFB was an effective nutrient supplement for mushroom cultivation substrate. E2 and E3 showed higher crude fiber, crude fat, soluble protein, and soluble sugar. Compared to CK, the content of monosodium glutamate-like (MSG-like) amino acids, essential amino acids, total amino acids and total 5'-nucleotides in E2 and E3 were higher. The equivalent umami concentration (EUC) values in E1, E2 and E3 were 1.70, 2.43 and 1.56 times of CK, respectively. Higher umami, saltness and sweetness taste values were found in E2. Thereby, it signified that better umami and richer nutrients were achieved by using substrate with proper volume of MRFB, especially, E2 with 13.4% of MRFB. Overall, better mushroom quality could be derived from the application of MRFB in cultivation. MRFB was a favorable nutrient supplement for Flammulina velutipes cultivation substrate.
ARTICLE | doi:10.20944/preprints202204.0116.v1
Subject: Chemistry, Food Chemistry Keywords: coffee pulp; coffee by-products; sensory evaluation; fruit spirit; methanol; distillation
Online: 13 April 2022 (05:09:35 CEST)
Coffee pulp, obtained from wet coffee processing, is the major by-product accumulating in the coffee producing countries. One of the many approaches valorising this underestimated agricultural residue is the production of distillates. This research project deals with the production of spirits from coffee pulp using three different Coffea arabica varieties as a substrate. Coffee pulp was fermented for 72 hours with a selected yeast strain (Saccharomyces cerevisiae L.), acid, pectin lyase, and water. Several parameters, such as temperature, pH, sugar concentration and alcoholic strength were measured to monitor the fermentation process. Subsequently, the alcoholic mashes were double distilled with stainless steel pot stills and a sensory evaluation of the products was conducted. Furthermore, the chemical composition of fermented mashes and produced distillates were evaluated. It showed that elevated methanol concentrations were present in mashes and products of all three varieties. The sensory evaluation found the major aroma descriptor for the coffee pulp spirits as being stone fruit. The fermentation and distillation experiments revealed that coffee pulp can be successfully used as a raw material for the production of fruit spirits. However, the spirit quality and its flavour characteristics can be improved with optimised process parameters and distillation equipment.
ARTICLE | doi:10.20944/preprints202204.0085.v1
Subject: Chemistry, Food Chemistry Keywords: aflatoxin M1; milk; dairy; cholesterol; β-cyclodextrin; food safety; global warming
Online: 11 April 2022 (03:18:05 CEST)
Approximately one-third of mankind is chronically exposed to the carcinogenic aflatoxin M1 contained in milk and dairy products and there is no ready to use procedure for decontamination purposes applicable in milk technology. Since β-cyclodextrin is frequently used in food industry, its effect on aflatoxin M1 concentration was investigated during cholesterol removal. So, milk samples were spiked with aflatoxin M1 at the average level 0.89 µg/kg and cholesterol removal was carried out by 2.0% (w/w) β-cyclodextrin addition. As found, average cholesterol concentration decreased by 92.3% while aflatoxin M1 concentration decreased to 0.53 µg/kg, i. e. by 39.1% after the treatment. The procedure itself is easy, inexpensive, and ready to use in milk processing technology on current production lines without any investments, thus fully applicable with a high potential of full aflatoxin M1 milk decontamination efficiency and such way to strengthen considerably the food safety issues associated with milk and dairy products on global level.
ARTICLE | doi:10.20944/preprints202201.0405.v1
Subject: Chemistry, Food Chemistry Keywords: mangosteen; phenolic components; HPLC; quantification; fingerprint
Online: 26 January 2022 (18:46:41 CET)
The extracts of Garcinia mangostana L. (mangosteen) are traditionally used for medicinal purposes in Asia. Phenols and xanthones are the two main phenolic compounds with anti-inflammatory activities in the pericarps of mangosteen. A simple and economic reverse-phase high-performance liquid chromatography (RP-HPLC) method has been developed for the simultaneous quantification of phenols (catechin, epicatechin, and procyanidin B2) in mangosteen. The mobile phase was acetonitrile: water (12:88) at 30°C, the flow rate was 1 mL/min, and the detection wavelength was 230 nm. The results showed good linear relationships for catechin from 50-250 ng and for epicatechin and procyanidin B2 from 250-1250 ng. The RP-HPLC fingerprint determination method of total xanthones in mangosteen was also established to provide a new method for quality control of mangosteen extract. The mobile phase was a methanol-water gradient elution at 30°C, the flow rate was 1 mL/min, and the detection wavelength was 320 nm. The similarity of fingerprints of 10 batches of total xanthones was more than 0.90. These methods had good precision, reproducibility, and stability and can be applied in the quality control of mangosteen extracts for medicinal purposes.
ARTICLE | doi:10.20944/preprints202201.0243.v1
Subject: Chemistry, Food Chemistry Keywords: aqueous micellar system; trypsin inhibitor; isoflavone extraction; non-ionic surfactant; multifactorial optimization
Online: 17 January 2022 (16:01:53 CET)
Simultaneous extraction of trypsin inhibitors and soy isoflavones from soybean meal was investigated using the non-destructive phytochemical extraction process, namely aqueous micellar system. The ethoxylated aliphatic alcohols Genapol X-080, Tergitol 15-S-7, and Tergitol 15-S-9, all non-toxic and biodegradable surfactants, were assessed as potential extractants. A Box-Behnken multifactorial design with the application of the Derringer desirability was used to determine the conditions that maximized the trypsin inhibitors and isoflavone extraction while minimizing the protein extraction. The optimum condition of 5% m/m of surfactant in 50 mM aqueous sodium citrate solution pH 4.5, at 45 °C for 45 min, was established for the three surfactants. The novel methodology would allow the extraction of the main soybean antinutritional factors, trypsin inhibitors, and the valuable isoflavones, preserving the nutritional quality of the treated material. This represents a sustainable alternative methodology for industrial purposes due to its low cost, biodegradability, non-toxicity, and easy scaling up.
ARTICLE | doi:10.20944/preprints202201.0217.v1
Subject: Chemistry, Food Chemistry Keywords: Nemipterus virgatus surimi; pre-emulsified safflower seed oil; gel texture; microstructure; flavor
Online: 14 January 2022 (16:12:29 CET)
Surimi-based products occupy an important position in the aquatic product processing industry. To enhance the quality and flavor of surimi-based products, the effects of pre-emulsified safflower seed oil on the texture, water-holding capacity (WHC), microstructure, and flavor of Nemipterus virgatus surimi gel was evaluated. The texture and whiteness of gel were improved, and the WHC increased (P < 0.05) as the content of safflower seed oil increased up to 2 mL per 100 g surimi. Furthermore, the drops of pre-emulsified safflower seed oils with an average diameter of less than 0.10 μm were evenly distributed in gel matrix. Microstructure and infrared spectroscopy analyses indicated that low-content pre-emulsified safflower seed oil acted as filler particles to occupy void spaces, resulting in gel exhibiting a dense network structure. Volatile analysis showed the gel containing pre-emulsified oil enriched volatile compounds, mainly resulting from oxidation and decomposition of oils by the activation of lipoxygenase, which synergistically contributes to unique flavors of gel. Consequently, low-content pre-emulsified safflower seed oil can used to enhance the quality and flavor of N. virgatus surimi-based products. These findings are especially relevant to the current growing interest in low-fat and high-protein diets.
ARTICLE | doi:10.20944/preprints202112.0425.v1
Subject: Chemistry, Food Chemistry Keywords: bioaccessibility; supercritical carbon dioxide; blackcurrant; vitamin C; anthocyanins; antioxidant activity; in vitro digestion model
Online: 27 December 2021 (11:24:51 CET)
Blackcurrant juice (Ribes nigrum L.) was subjected to supercritical carbon dioxide (SCCD) at 10, 30 and 60 MPa for 10 min at 45°C as well as thermally treated at 45°C and 85°C for 10 min to determine the stability, antioxidant capacity (AC) and bioaccessibility (BAc) of vitamin C, total anthocyanins and their individual monomers. An in vitro gastrointestinal digestion model completed with dialysis was used to assess BAc. The use of SCCD at each of the pressures applied improved the stability of vitamin C, total anthocyanins, and AC before in vitro digestion. As a result of digestion, L-ascorbic acid was oxidized to L-dehydroascorbic acid, and finally, the total content of vitamin C, anthocyanins, and AC decreased. SCCD did not significantly improve the BAc of vitamin C and total anthocyanins. The highest BAc of vitamin C was noted in fresh juice (FJ) (40%) and after mild heat treatment at 45°C (T45) (46%). The highest BAc of total anthocyanins was also noted in the FJ (4.4%). The positive effect of the application of SCCD on the BAc of the delphinidin-3-O-glycosides was observed compared to T45 and thermal pasteurization at 85°C (T85). Moreover, cyanidins were generally more bioaccessible than delphinidins in all samples. AC after digestion was higher in SCCD samples compared to thermally treated measured using ABTS+• and DPPH• assays, whereas in dialysate similar trends were observed only for AC measured using the ABTS+• assay. This phenomenon was justified by the formation of individual metabolites detected by UPLC-PDA-MS / MS in the model experiment with delphinidin-3-O-rutinoside. The protocatechuic acid which is well known as a strong antioxidant was detected in the model experiment after digestion. Further research is needed to better understand the metabolic pathway of anthocyanins and the possible uses of SCCD to improve the health properties of fruit products.
COMMUNICATION | doi:10.20944/preprints202112.0291.v1
Online: 17 December 2021 (14:46:05 CET)
Hydrogel antibacterial agent is an ideal antibacterial material because of it could diffuses antibacterial molecules into the decayed area by providing a suitable microenvironment and the hydrogel acts as a protective barrier on the decay interface. The biocompatibility and biodegradation make the removal process easily which were widely used in medical fields. However, there have been few reports on its application for controlling postharvest diseases in fruit. In this study, the Chitosan-Ag (CS-Ag) complex hydrogels were prepared using the physical crosslinking method, which used for controlling postharvest diseases in grape. The prepared hydrogels were stable for a long period at room temperature. The structure and surface morphology of CS-Ag composite hydrogels were characterized by UV-Vis, FTIR, SEM, and XRD. The inhibitory effects of CS-Ag hydrogel on disease in grape caused by P. expansum, A. niger and B. cinerea were investigated both in vivo and in vitro. The remarkable antibacterial activity of CS-Ag hydrogels was mainly due to the synergistic antibacterial and antioxidant effects of CS and Ag. Preservation test showed that the CS-Ag hydrogel had positive fresh-keeping effect. This revealed CS-Ag hydrogels plays a critical role in controlling fungal disease in grape.
ARTICLE | doi:10.20944/preprints202112.0058.v1
Subject: Chemistry, Food Chemistry Keywords: proton-coupled electron transfer; superoxide radical anion; antioxidants; cyclic voltammetry; electron spin resonance spectrum; tocopherol
Online: 3 December 2021 (15:01:26 CET)
Abstract: Elimination of superoxide radical anion (O2•−) by tocopherols (TOH), and related compounds was investigated on the basis of cyclic voltammetry and in situ electrolytic electron spin resonance spectral measurements in N,N-dimethylformamide (DMF) with the aid of density functional theory (DFT) calculations. Quasi-reversible O2/O2•− redox was modified by the presence of TOHs, suggesting that the electrogenerated O2•− was eliminated by α-, β-, γ-TOH through proton-coupled electron transfer (PCET), but not by δ-TOH. The structure–activity correlation of α-, β-, γ-, and δ-TOH characterized by methyl group on the 6-chromanol ring was experimentally confirmed, where the methyl group promotes the PCET mechanism. Furthermore, comparative analyses using some related chemical analogues suggested that methoxyl group of the 6-chromanol ring is required for a successful electron transfer (ET) to O2•− through the PCET. The electrochemical and DFT results in dehydrated DMF suggested that the PCET mechanism involves preceding proton transfer (PT) forming hydroperoxyl radical followed by a concerted PCET (ET–PT). The O2•− elimination by TOH proceeds efficiently along the net PCET mechanism involving one ET and two PTs.
ARTICLE | doi:10.20944/preprints202111.0093.v1
Subject: Chemistry, Food Chemistry Keywords: waxy rice starch; α-amylase; protein; amylopectin structure
Online: 4 November 2021 (08:00:31 CET)
Waxy rice is one of the most popular traditional crops served as a staple food in China. In this study, the effect of different factors including α-amylase activity, protein, and amylopectin structure on the pasting properties of four waxy rice varieties were investigated. Rice flours treated with AgNO3 solution, DL-dithiothreitol (DTT) or protease, suggested that both α-amylase activity and protein significantly decrease the pasting viscosity of waxy rice flours. Chain length distribution of amylopectin as measured by high performance ion exchange chromatography (HPAEC-PAD) showed that starch with higher ratio of short chain leading to a higher pasting viscosity. X-Ray diffractograms showed that the crystal type of all the four varieties of rice starches were characteristic A-type. Relative crystallinity of each rice starch was further calculated, and a higher crystallization resulted in a higher viscosity. Our study would provide a fundamental knowledge of the relationship between different factors and waxy starch pasting properties, as well as be a reference for controlling the quality of waxy rice starch-based food.
ARTICLE | doi:10.20944/preprints202110.0267.v1
Subject: Chemistry, Food Chemistry Keywords: myofibrillar protein; sulfhydryl-blocking agent; disulfide bond; protein-stabilized emulsions; interface protein membrane
Online: 19 October 2021 (10:21:59 CEST)
To investigate the role of sulfhydryl groups and disulfide bonds in different protein-stabilized emulsions, N-ethylmaleimide (NEM) was used as sulfhydryl-blocking agent to be added in the emulsion. The addition of NEM to block the sulfhydryl groups resulted in a reduction of the content of disulfide bonds formation, which enabled destruction of the internal structure of the protein molecule, and then decreased the restriction of protein membrane on the oil droplets. Furthermore, with NEM content increasing in the emulsion, a reduction of protein emulsifying activity and emulsion stability also occurred. At the same time, the intermolecular interaction of the protein on the oil droplet interface membrane was destroyed, and the emulsion droplet size increased with the NEM content in the emulsion. Although NEM blocking sulfhydryl groups not to form disulfide bonds has similar effects on three types of protein emulsion, the degree of myofibrillar protein (MP), egg-white protein isolate (EPI), and soybean protein isolate (SPI) as emulsifier had a subtle difference.
Subject: Chemistry, Food Chemistry Keywords: pomegranate tannins; ellagic acid; molecular modelling; α2-adrenoreceptors; α2-ARs; molecular dynamic simulations; antioxidant; natural compounds; antidepressant activity; food chemistry
Online: 1 October 2021 (14:27:20 CEST)
Polyphenol ellagic acid (EA) possesses anti-oxidant, anti-inflammatory, anti-carcinogenic, anti-diabetic and cardio protection activities, remarking it an interesting multi-targeting profile. EA also controls the central nervous system (CNS) since it was proven to reduce the immobility time of mice in both the forced swimming and the tail-suspension tests, with an efficiency comparable to that of classic antidepressants. Interestingly, the anti-depressant-like effect was almost nulled by the concomitant administration of selective antagonists of the noradrenergic receptors, suggesting the involvement of these cellular targets in the central effects elicited by EA and its derivatives. By in silico and in vitro studies, we discuss how EA engages with human α2A-ARs and α2C-AR catalytic pockets, comparing EA behaviour with those ones of known agonist and antagonist. Structurally, the hydrophobic residues surrounding α2A-AR pocket confer specificity on the intermolecular interactions and hence lead to favourable binding of EA in the α2A-AR, with respect to α2C-AR. Moreover, EA seems to better accommodate within α2A-ARs into TM5 area, closely to S200 and S204 which play a crucial role for activation of aminergic GPCRs such as the α2-AR, highlighting its promising role as a partial agonist. Consistently, EA mimics clonidine in inhibiting noradrenaline exocytosis from hippocampal nerve endings in an yohimbine-sensitive fashion that confirms the engagement of naïve α2-ARs in the EA-mediated effect.
ARTICLE | doi:10.20944/preprints202109.0081.v1
Subject: Chemistry, Food Chemistry Keywords: rootstocks; untargeted metabolomics; features; grafted; multivariate analysis; volatile compounds
Online: 6 September 2021 (09:52:40 CEST)
To allow for a broad survey of subtle metabolic shifts in wine caused by rootstock and irrigation, an integrated metabolomics-based workflow followed by quantitation was developed. This workflow was particularly useful when applied to a poorly studied variety cv. Chambourcin. Allowing volatile metabolites that otherwise may have been missed with a targeted analysis to be included, this approach allowed deeper modeling of treatment differences which then could be used to identify important compounds. Wines produced on a per vine basis, over two years, were analyzed using SPME-GC-MS/MS. From the 382 and 221 features that differed significantly among rootstocks in 2017 and 2018 respectively, we tentatively identified 94 compounds by library search and retention index, with 22 confirmed and quantified using authentic standards. Own-rooted Chambourcin differed from other root-systems for multiple volatile compounds with fewer dif-ferences among grafted vines. For example, the average concentration of β-Damascenone present in own-rooted vines (9.49 µg/L) was significantly lower in other rootstocks (8.59 µg/L), whereas mean Linalool was significantly higher in 1103P rootstock compared to own-rooted. β-Damascenone was higher in regulated deficit irrigation (RDI) than other treatments. The workflow outlined not only was shown to be useful for scientific investigation, but also in creating a protocol for analysis that would ensure differences of interest to industry are not missed.
REVIEW | doi:10.20944/preprints202108.0188.v1
Online: 9 August 2021 (10:09:30 CEST)
Taro is an important root vegetable and has several medicinal and therapeutic properties. The two major therapeutic ingredients are flavonoids and triterpenoids, which are of prime importance. Additionally, the plant has antibacterial, antiparasitic, antiallergic, and anti-inflammatory properties. People often use it to treat a number of diseases by prescribing them as medications. Researchers from the pharmaceutical industry can thrive on C. esculenta by using whole-plant extracts. The identification of valuable terpenoids and therapeutics and their preparations are profusely dealt with in this article. Also, the new structural details of connective tissue are also studied as it helps researchers to investigate further uses of taro for humans, it is well known that xanthan can be obtained commercially as stabilizers, thickeners, binders, and more. It is essential to explore this plant for both medicinal and pharmaceutical properties.
ARTICLE | doi:10.20944/preprints202108.0096.v1
Subject: Chemistry, Food Chemistry Keywords: Qinling mountains; Wild Chinese prickly ashes; HPLC fingerprint; Resource evaluation.
Online: 3 August 2021 (15:55:32 CEST)
Wild Chinese prickly ash with elevated antioxidants is a valuable genetic resource for Zanthoxylum bungeanum Maxim improvement. There are rich wild germplasm resources in the Qinling Mountains. In a study with wild germplasm resources from different altitudes and six cultivated varieties, the phenolic and flavonoid compounds were analyzed by high performance liquid chromatography (HPLC). The chromatograms of them were basically the same, although their chemical composition content was greatly different. The thirty samples were divided into three categories through the hierarchical clustering analysis. And catechin, hyperoside and quercitrin were considered to be key compound for the quality evaluation, by contrast, the wild samples with an altitude of 2300±50 m (Ⅳ group) had the highest content of key compounds, and showed stronger antioxidant activity and antibacterial ability, indicating that these wild samples could be used as an excellent breeding resource. This is the first time to evaluate the quality of wild Chinese prickly ash in different altitude areas of Qinling Mountains. These excellent wild germplasm resources provided substantial potential accessions for use directly in Chinese prickly ash breeding programs.
ARTICLE | doi:10.20944/preprints202106.0248.v1
Subject: Chemistry, Food Chemistry Keywords: post-harvest; grape; wine; withering; stilbenes; aroma; Amarone; Corvina
Online: 9 June 2021 (09:03:25 CEST)
In the Valpolicella area (Verona - Italy) Vitis vinifera cv. Corvina is the main grape variety used to produce Amarone wine. Before starting the winemaking process, the Corvina grapes are stored in a withering (i.e., dehydrating) warehouse until about 30% of the berry weight is lost (WL). This practice is followed to have the chemical metabolites concentrate in the berry and enrich the Amarone wine in aroma and antioxidant compounds. In compliance with the guidelines and strict Amarone protocol set by the Consorzio of Amarone-Valpolicella, withering must be carried out by setting the grapes in a suitable environment, either under controlled relative air humidity (RH) conditions and wind speed (WS) – no temperature modification is to be applied – or, following the traditional methods, in open-air natural environmental conditions. In general, the two processes have different dehydration kinetics due to the different conditions in terms of temperature, RH, and WS, which affect the accumulation of sugars and organic acids and the biosynthesis of sec-ondary metabolites such as stilbenes and glycoside aroma precursors. For this study, the two grape-withering processes were carried out under controlled (C) and not-controlled (NC) condi-tions and the final compositions of the Corvina dried grapes were compared also to evaluate the effects on the organoleptic characteristics of Amarone wine. The findings highlighted differences between the two processes mainly in terms of the secondary metabolites of the dried grapes, which affect the organoleptic characteristics of Amarone wine.
ARTICLE | doi:10.20944/preprints202105.0393.v1
Subject: Chemistry, Food Chemistry Keywords: cannabidiol (CBD); ∆9-tetrahydrocannabinol (∆9-THC); cannabinol (CBN); ∆8-tetrahydrocannabinol (∆8-THC); cannabinoids; CBD oil; nuclear magnetic resonance spectroscopy (NMR); PULCON methodology; 1H NMR; qNMR
Online: 17 May 2021 (16:56:15 CEST)
Toxicologically relevant levels of the psychoactive ∆9-tetrahydocannabinol (∆9-THC) as well as high levels of non-psychoactive cannabinoids potentially occur in CBD (cannabidiol) oils. For consumer protection in the fast-growing CBD oil market, facile and rapid quantitative methods to determine the cannabinoid content are crucial. However, the current standard method, i.e., liquid chromatography combined with tandem mass spectrometry (HPLC-MS/MS), requires a time-consuming multistep sample preparation. In this study, a quantitative nuclear magnetic resonance spectroscopy (qNMR) method for screening cannabinoids in CBD oils was developed. Contrary to the HPLC-MS/MS method, this qNMR features a facile sample preparation, i.e., only diluting the CBD oil in deuterochloroform. Pulse length-based concentration determination (PULCON) enables a direct quantification using an external standard. The signal intensities of the cannabinoids were enhanced during the NMR spectra acquisition by means of multiple suppression of the triglycerides which are a major component of the CBD oil matrix. The validation confirmed linearity for CBD, cannabinol (CBN), ∆9-THC and ∆8-THC in hemp seed oil with sufficient recoveries and precision for screening. Comparing the qNMR results to HPLC-MS/MS data for 46 commercial CBD oils verified the qNMR accuracy for ∆9-THC and CBD but with higher limits of detection. The developed qNMR method paves the way for increasing the sample throughput as a complementary screening before HPLC-MS/MS.
ARTICLE | doi:10.20944/preprints202102.0620.v1
Subject: Chemistry, Food Chemistry Keywords: IntegroPectin, naringin, eriocitrin, citrus, flavonoids, pectin, circular economy
Online: 26 February 2021 (13:47:16 CET)
Following the analysis of terpenes present in new lemon and grapefruit “IntegroPectin” pectins obtained via the hydrodynamic cavitation of industrial lemon and grapefruit processing waste, the HPLC-MS analysis of the flavonoid compounds reveals the presence of eriocitrin, naringin, hesperidin and kaempferol typical of the respective citrus fruits. The pectic fibers rich in rhamnogalacturonan-I “hairy” regions act as chemical sponges adsorbing and concentrating at their outer surface highly bioactive citrus flavonoids and terpenes. These findings, together with the unique molecular structure of these new whole citrus pectins, provide preliminary insight into the broad-scope and powerful biological activity of these biomaterials. Numerous new biomedical applications beyond prevention and treatment of microbial infections and neurodegenerative disease are anticipated.
ARTICLE | doi:10.20944/preprints202009.0317.v1
Subject: Chemistry, Food Chemistry Keywords: ICP-MS; trace elements; wine; Nizza; Barbera; authentication
Online: 14 September 2020 (00:49:48 CEST)
Barbera d'Asti - including Barbera d'Asti superiore - and Nizza are two DOCG (Denominazione di Origine Controllata e Garantita) wines produced in Piemonte (Italy) from Barbera grape variety. Differences among them arise in the production specifications in terms of purity, ageing and zone of production, in particular with concern to Nizza, which has more stringent rules and can therefore be considered as the one with the highest market value, with even three-fold more average prices. To guarantee producers and consumers, authentication methods must be developed in order to distinguish among the different wines. As the production zones totally overlap, it is important to verify whether the distinction is possible or not according to metals content, or whether chemical markers more linked to winemaking are needed. In this work, Inductively Coupled Plasma (ICP) elemental analysis and multivariate data analysis are used to study the authentication and traceability of samples from the three designations of 2015 vintage. The results show that, as far as elemental distribution in wine is concerned, work in the cellar, rather than geographic provenance, is crucial for the possibility of distinction.
ARTICLE | doi:10.20944/preprints202009.0255.v1
Subject: Chemistry, Food Chemistry Keywords: antioxidant enzymes; hydrogen peroxide; phenylalanine ammonia-lyase; proline; scanning electron microscopy
Online: 11 September 2020 (09:58:41 CEST)
Susceptibility of four blood orange cultivars (‘Moro’, ‘Tarocco’, ‘Sanguinello’ and ‘Sanguine’) to chilling injury (CI) was studied. Antioxidant enzymes, physiological and biochemical changes were measured monthly at 2 and 5 °C plus 2 days at 20 °C for shelf life. At 2 °C, CI symptoms were higher than at 5 °C, and ‘Moro’ and ‘Tarocco’ had significantly higher CI than ‘Sanguinello’ and ‘Sanguine’. ‘Moro’ and ‘Tarocco’ had the highest electrolyte leakage, malondialdehyde, H2O2 and polyphenol oxidase activity and lower phenylalanine ammonia-lyase compared with ‘Sanguinello’ and ‘Sanguine’. The scanning electron microscopy micrographs revealed that ‘Moro’ and ‘Taroco’ showed severe fractures in the flavedo due to CI. ‘Sanguinello’ and ‘Sanguine’ were more tolerant to CI due to an increase of catalase, ascorbate peroxidase and superoxide dismutase, which could prevent the loss of membrane integrity and alleviate CI symptoms. The order of susceptibility of cultivars to CI was ‘Moro’> ‘Tarocco’> ‘Sanguine’> ‘Sanguinello’.
ARTICLE | doi:10.20944/preprints202009.0231.v1
Subject: Chemistry, Food Chemistry Keywords: organic acids; sugars; anthocyanins; antioxidant enzymes; ascorbic acid
Online: 10 September 2020 (09:11:16 CEST)
The changes in nutritional quality, bioactive compounds and antioxidant enzymes in the juice of four blood orange cultivars (‘Moro’, ‘Tarocco’, ‘Sanguinello’ and ‘Sanguine’) stored during 6 months at 2 and 5 °C plus 2 days at 20 °C for shelf life were studied. Sucrose was the sugar found at higher concentration and decreased during storage for all cultivars, as did glucose and fructose. Organic acids decreased at both temperatures and the highest content was found in ‘Sanguinello’, especially the major (citric acid) and ascorbic acid. Total phenolics content (TPC), total anthocyanins (TAC), and the individual (cyanidin 3-glucoside and cyanidin 3-(6″-malonylglucoside)) increased for all cultivars, the ‘Sanguinello’ having the higher concentrations. Antioxidant enzymes catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were higher also in ‘Sanguinello’ and increased during storage. Overall, these results together with the sensory analysis suggest that ‘Sanguinello’ would be the best cultivar for prolonged storage.
ARTICLE | doi:10.20944/preprints202008.0713.v1
Subject: Chemistry, Food Chemistry Keywords: NMR; alcoholic beverages; ethanol; methanol; acetaldehyde; screening; validation; food control; PULCON
Online: 31 August 2020 (06:21:35 CEST)
Due to legal regulations, the rise of globalised (online) commerce and the need for public health protection, the analysis of spirits (alcoholic beverages > 15 % vol) is a task with growing importance for governmental and commercial laboratories. In this article a newly developed method using nuclear magnetic resonance (NMR) spectroscopy for the simultaneous determination of 15 substances relevant for the quality and authenticity assessment of spirits is described. The new method starts with a simple and rapid sample preparation and does not need an internal standard. For each sample a group of 1H-NMR spectra is recorded, among them a 2D spectrum for analyte identification and 1D spectra with suppression of solvent signals for quantification. Using the Pulse Length Based Concentration Determination (PULCON) method, concentrations are calculated from curve fits of the characteristic signals for each analyte. The optimisation of the spectra, their evaluation and the transfer of the results are done fully automatically. Glucose, fructose, sucrose, acetic acid, citric acid, formic acid, ethyl acetate, ethyl lactate, acetaldehyde, ethanol, methanol, n-propanol, isobutanol, isopentanol, 2-phenylethanol and 5-(hydroxymethyl)furfural (HMF) can be quantified with an overall accuracy better than 8 %. This new NMR-based targeted quantification method enables the simultaneous and efficient quantification of relevant spirits ingredients in their typical concentration ranges in one process with good accuracy. It has proven to be a reliable method for all kinds of spirits in routine food control.
ARTICLE | doi:10.20944/preprints202008.0052.v1
Subject: Chemistry, Food Chemistry Keywords: Spray Drying; Vitamin C; Phenolic Compounds; Preservation; Modeling; Optimization
Online: 2 August 2020 (18:22:59 CEST)
Umbu is a tropical fruit with high content of bioactive compounds. However, maturation causes significant losses on nutrient density reducing the nutritional value of this highly appreciated fruit. Thus, the objective of the present work was to encapsulate the Umbu fruit bioactive compounds using spray drying and identify the variables affecting the biomolecules preservation. A Box-Behnken experimental design with 3 factors was set varying inlet temperature, atomization flow rate, and maltodextrin concentration for process otimization. Then the powder physicochemical and chemical properties were characterized, and results were modeled using a polynomial equation. Results revealed that the droplet size and maltodextrin concentration had a significant influence on the conservation of the biomolecules. Drying kinetics favoring fast formation of a particle crust increases encapsulation efficiency. Bioactive compounds retention was achieved by increasing maltodextrin even at high temperatures, where a matrix is formed hindering chemical degradation. Process optimization was validated and revealed low inlet temperatures (122ºC), high atomization flow rate (5kg/h) and high maltodextrin concentration (20%) to be the most desirable conditions for bioactive compounds retention.
ARTICLE | doi:10.20944/preprints202007.0221.v1
Subject: Chemistry, Food Chemistry Keywords: hCA IX and XII; dual inhibitors; molecular modeling studies; in vitro assays
Online: 11 July 2020 (02:30:03 CEST)
The tumour-associated isoenzymes, hCA IX and hCA XII catalyze the hydration of carbon dioxide to bicarbonate and protons. These isoforms are highly overexpressed in many types of cancer, where they contribute for the acidification of the tumor environment promoting the tumor cell invasion and metastasis. In this work, in order to identify novel dual hCA IX and XII inhibitors, virtual screening techniques and biological assays were combined. A structure based virtual screening towards hCA IX and XII was performed using a database of approximately 26000 natural compounds. The best shared hits were submitted to a thermodynamic analysis and 3 promising best hits were identified and evaluated in terms of their hCA IX and XII inhibitor activity. In vitro biological assays are in line with the theoretical studies and revealed that Syringin, Lithospermic acid, and (-)- Dehydrodiconiferyl alcohol behave as good hCA IX and hCA XII dual inhibitors.
ARTICLE | doi:10.20944/preprints202007.0076.v1
Subject: Chemistry, Food Chemistry Keywords: coffee; cold brew; nitro cold brew; roasting; extraction; hygiene; risk assessment; product quality
Online: 5 July 2020 (14:53:27 CEST)
Cold brew coffee has emerged as a new trend during the last decade. However, “cold brew” is an extraction style of ground roasted coffee with water at less than body temperature (typically 8°C or room temperature) rather than a beverage per se. Cold brew extraction poses several challenges including the need of specific optimization depending on the multivariate influences of coffee variety and processing, roast degree, grinding, dosage, water composition, turbulence, brew system (drip, immersion etc.), time and temperature. While cold brew is typically characterized by a floral sweetness, over-extraction may lead to abundant acidity and bitterness. To avoid this, an extraction degree of 70% was suggested using rather shorter times (i.e. 2 h at 15°C with 80 g/L coffee with optimized medium roast profiles). Due to the lack of sterilizing temperatures during preparation, cold brew is special in the coffee sector because hygiene and food safety aspects pose specific challenges for food industry. To avoid microbiological contamination and spoilage, cold brew should be as freshly prepared as possible and shelf-life should be minimized.
Subject: Chemistry, Food Chemistry Keywords: Nutrition system; Carbon footprint; Energy metabolism; Anthropometric; Biomedical treatment
Online: 31 May 2020 (21:01:47 CEST)
To reduce the risk factors for mortality, the paper has focused on the assessment of the socioeconomic, clinical, physical, biophysiological, and biochemical characteristics of Down's syndrome which can be affected by the type of nutrition system, toxicity, and ecological footprint. Patients were males with trisomy 21 diagnosed by karyotype test and assessed by clinical examinations. Samples were collected from different biofluids. The physicochemical analyses of the biomatrix samples were performed and these properties had compared to findings of healthy males and age-matched controls. Duraphat application was proved effective for their oral treatment and saliva was the optimum biomarker for detecting malnutrition. Patients were hypersensitive to Cu while the Mn content in blood and hair was considered an expression to the degree of epileptic condition and chronic seizure development. The ecological footprint was 5.6 gha and carbon footprint was recognised in food poverty habits. These can be reduced by eating more plant-based proteins and fibre-rich foods with low saturated fats and sodium. The findings provide an up-to-date reference for expected developmental outcomes in children with DS in terms of biophysicochemistry. The genetically sensitive intervention is affected by heredity factor and sensitivity to toxics. Down's syndrome is encouraged to live green-hipster life.
ARTICLE | doi:10.20944/preprints202003.0368.v1
Subject: Chemistry, Food Chemistry Keywords: phase equilibrium; in vitro lipid digestion; fats and oils
Online: 25 March 2020 (04:14:17 CET)
The absorption of medium-chain fatty acids (MCFA) depends on the solubility of these components in the gastric fluid. Parameters such as the total MCFA concentration, carboxyl ionization level, and carbon chain length affect the solubility of these molecules. Moreover, the enzymatic lipolysis of solubilized triacylglycerol (TAG) molecules may depend on the carbon chain length of the fatty acids (FAs) components and their positions on the glycerol backbone. This present study aimed at investigating the effect of electrolyte usually formed during the gastric digestion phase on the solubility of MCFA, and evaluating the influence of the FA carbon chain length on the lipolysis rate during the in vitro digestion simulation. The results obtained here showed that the increasing of electrolyte concentrations tend to decrease the mutual solubility of systems composed by the caproic and caprylic fatty acids + sodium chloride, sodium bicarbonate, and potassium chloride solutions. We also observed that a conventional version of the thermodynamic UNIQUAC model was able to correlate the liquid-liquid phase behavior of the electrolyte solutions. Regarding the in vitro digestion simulation, the experimental data indicated that the action of the pancreatic enzyme occurred preferentially in TAG molecules comprised of short and medium-chain fatty acids.
Subject: Chemistry, Food Chemistry Keywords: dried Chinese sausage; fat replacement; mango peel pectin; microwave-assisted extraction technique
Online: 11 March 2020 (03:07:13 CET)
In this research, low-fat dried Chinese sausage was formulated with mango peel pectin (MPP) extracted by microwave assisted extraction (MAE) (0%, 5%, 10% and 15% (w/w). The extractable yield of pectin attained from peel of Nam Dok Mai variety was achieved at 13.85% using 700-watt power. The extracted MPP were of high equivalent weight (1,485.78 mg/mol), degree esterification (77.19%) and methoxyl content (19.33%) with the structure of more porosity as compared to that of the conventional method. Spectrum scans by Fourier transform infrared spectrophotometer (FT-IR) advised that the extracted MPP gave the similar wave number profiles as the commercial pectin. Quality attributes of the Chinese sausages were accessed and compared with the control formula (CTRL). At higher concentrations of MPP, the product had positively increased colour intensity. The texture profile of the sausage illustrated that only the hardness value was comparable with the CTRL, while springiness, cohesiveness, gumminess and chewiness were statistically lower (p < 0.05). Furthermore, the sensory evaluation by experienced panellists (n=12) indicated that 5% MPP similarly represented overall acceptability with the CTRL. Consequently, MPP can be effectively applied at low level as fat replacement in Chinese sausage allowing colour improvement and product of healthier option.
ARTICLE | doi:10.20944/preprints202002.0274.v1
Subject: Chemistry, Food Chemistry Keywords: Chemical profiles; taxonomical description; volatile compositions; Zanthoxylum spp.
Online: 19 February 2020 (10:54:48 CET)
In order to obtain makhwean (MK) fruit essential oil of constant aromatic profile during raw material sourcing, evaluation of relationship between genotype, phenotype and chemical profiles are necessary. Three specimens of the MK (MK1-3) distributed in Northern Thailand were genetically and morphologically compared with other Zanthoxylum spices known locally as mamaad (MM) and makwoung (MKO), respectively. MM was taxonomical confirmed as Z. armatum based on plant structure and leaf characteristic (Odd-pinnately compound leaf). MKO and MK were identified as Z. rhetsa and Z. myriacanthum using number of petals and anthers. Genetic sequencing by Internal Transcribed Spacer (ITS) sequence and Random Amplified Polymorphic DNA moreover, divided these Zanthoxylum spps. into three groups accordingly to their species viz., MM, MKO and MK. Essential oil of the dried fruits from these samples was extracted and analysed for physical and chemical profiles. Cluster analysis (PCA-biplot) of volatile compositions was able to separate 1) MK1 and MK3 with limonene as leading component, 2) MK2 and MKO related with sabinene and β-philandrene, 3) MM with linalool. By using odour attribute representatives, the essential oil of MKO and MK1-3 were closely related possessing fruity, woody and citrus aromas, while the MM was sweet/ floral. In summary for MK raw material sourcing, plant genotyping played the most important role to odour characteristics than growing locations, thus plant species confirmation should be first considered.
ARTICLE | doi:10.20944/preprints202001.0141.v1
Subject: Chemistry, Food Chemistry Keywords: elderberry minerals; antioxidant activity; phenolic compounds; anthocyanins.
Online: 14 January 2020 (12:08:35 CET)
This study compared the mineral content and bioactive properties of flowers and fruit coming from wild elderberry plants with those of flowers and fruit harvested from elderberry cultivars grown in an orchard. Elderberry fruit and flowers were analysed for the content of selected minerals, phenolic compounds and anthocyanins and for antioxidant activity. Mineral content was determined by atomic absorption spectrometry method, while antioxidant activity and the content of polyphenols and anthocyanins were determined by spectrophotometric methods. Flowers were found to contain more total ash and to have much higher content of most of minerals, except magnesium, which was present in high concentrations in fruit. Fruit showed significantly higher antioxidant activity than flowers, whereas the total phenolic content varied depending on the growing location / cultivar. The material obtained from selected cultivars growing in an orchard had higher antioxidant activity and polyphenol and anthocyanin content than the material obtained from wild plants. Fruit of the ‘Haschberg’ cultivar and flowers of the ‘Sampo’ cultivar had the best bioactive properties of the studied samples.
ARTICLE | doi:10.20944/preprints201911.0390.v1
Subject: Chemistry, Food Chemistry Keywords: caffeine; 16-O-methylcafestol; kahweol; furfuryl alcohol; tetramethylsilan (TMS); magnetic resonance spectroscopy; validation studies
Online: 30 November 2019 (10:20:17 CET)
Monitoring coffee quality as a means of detecting and preventing economically motivated fraud is an important aspect of international commerce today. Therefore, there is a compelling need for rapid high throughput validated analytical techniques such as quantitative proton NMR spectroscopy for screening and authenticity testing. For this reason, we sought to validate an NMR spectroscopic method for routine screening of coffee for quality and authenticity. A factorial experimental design was used to investigate the influence of NMR device, extraction time and nature of coffee on the content of caffeine, 16-O-methylcafestol (OMC), kahweol, furfuryl alcohol and 5-hydroxymethylfurfural (HMF) in coffee. The method was successfully validated for specificity, selectivity, sensitivity and linearity of detector response. The proposed method produced satisfactory precision for all analytes in roasted coffee, except for kahweol in canephora (robusta) coffee. The proposed validated method may be used for routine screening of roasted coffee for quality and authenticity control, as its applicability was demonstrated during the recent OPSON VIII Europol-Interpol operation on coffee fraud control.
COMMUNICATION | doi:10.20944/preprints201910.0352.v1
Subject: Chemistry, Food Chemistry Keywords: coffee; espresso; hot beverages; temperature; esophageal cancer; sensory trial
Online: 30 October 2019 (09:12:32 CET)
Very hot (> 65 °C) beverages such as espresso were evaluated by the International Agency for Research on Cancer (IARC) as probably carcinogenic to humans. For this reason, research into lowering beverage temperature without compromising its quality or taste is important. For espresso, one obvious possibility consists in lowering the brewing temperature. In two sensory trials using ISO 4120:2004 triangle test methodology, brewing temperatures of 80°C vs. 128°C and 80° vs. 93°C were compared. From the tested levels, espresso brewed at the lowest temperature had the highest acceptance. However, most tasters were unable to distinguish between 80°C and 93°C. The results of these pilot experiments proof the possibility to decrease the health hazard of very hot beverages by lower brewing temperatures.
ARTICLE | doi:10.20944/preprints201910.0007.v1
Subject: Chemistry, Food Chemistry Keywords: terpenoids; Vibrio fischeri; toxicity; QSAR; heuristic method
Online: 2 October 2019 (02:55:05 CEST)
Terpenoids, including monoterpenoids (C10), norisoprenoids (C13) and sesquiterpenoids (C15), constitute a large group of plant-derived naturally occurring secondary metabolites which chemical structure is highly diverse. A quantitative structure-activity relationship (QSAR) model to predict the terpenoids toxicity and to evaluate the influences of their chemical structure, was developed in this study, by assessing the toxicity of 27 terpenoid standards using Gram-negative bioluminescent Vibrio fischeri, in real time. Under the test conditions, at concentration of 1 µM, the terpenoids showed a toxicity level lower than five %, with exception of geraniol, citral, (S)-citronellal, geranic acid, (±)-α-terpinyl acetate and geranyl acetone. Moreover, the standards tested displayed a toxicity level higher than 30 % at concentration of 50 to 100 µM, with the exception of (+)-valencene, eucalyptol, (+)-borneol, guaiazulene, β-caryophellene and linalool oxide. Regarding the functional group, the terpenoids toxicity was observed in the following order: alcohol > aldehyde ~ ketone > ester > hydrocarbons. CODESSA software was employed to develop the QSAR models based on the correlation of terpenoids toxicity and a pool of descriptors related to each chemical structure. The QSAR models, based on t-test values, showed that terpenoids toxicity was mainly attributed to geometric (e.g., asphericity) and electronic (e.g., max partial charge for a C atom [Zefirov's PC]) descriptors. Statistically, the most significant overall correlation was the four-parameter equation with training and test coefficient correlation higher than 0.810 and 0.535, respectively, and square coefficient of cross-validation (Q2) higher than 0.689. According to the obtained data, the QSAR models are a suitable and a rapid tool to predict the terpenoids toxicity in a diversity of food products.
ARTICLE | doi:10.20944/preprints201908.0093.v2
Subject: Chemistry, Food Chemistry Keywords: spent coffee grounds; polyphenols; extraction; subcritical fluid; activated carbon; methylene blue; adsorption.
Online: 20 September 2019 (10:23:51 CEST)
A valorization process of spent coffee grounds (SCG) was studied. Thus, a two-stage process, a stage of extraction of the polyphenols and a stage of obtaining activated carbon (AC) by a carbonization process, was performed. The extraction was carried out with a hydro-alcoholic solution in a pressure reactor, modifying time and temperature. To optimize the extraction of polyphenols, a two-level factorial design with three replications at the central values was used. The best results were obtained by performing the extraction at 80 °C during 30 min, using a mixture of EtOH:H2O 1:1 (v/v) as extraction solution. Caffeine and chlorogenic acid were the most abundant compounds in the analyzed extracts, ranging from 0.09 to 4.8 mg∙g-1 and 0.06 to 9.7 mg∙g-1, respectively. The precursor obtained in the extraction stage were transformed into AC. An experimental design was realized in order to analyze the influence of different variables in the AC obtained process (reaction time and amount of potassium hydroxide used). Actived carbons with BET specific surface (SBET) comprised between 1600 m2∙g-1 and 2330 m2∙g-1 had a microporous surface. Under the optimum conditions, the obtained AC presented a maximum adsorption capacity of methylene blue (qm) between 411 mg∙g-1 and 813 mg∙g-1.
ARTICLE | doi:10.20944/preprints201907.0325.v1
Subject: Chemistry, Food Chemistry Keywords: biomethane; d-limonene; flavanones; food waste; green extraction; hydrodynamic cavitation; orange waste; pectin; polyphenols
Online: 29 July 2019 (04:04:30 CEST)
Waste orange peel represents a heavy burden for the orange juice industry, estimated in several million tons per year worldwide; nevertheless, this by-product is endowed with valuable bioactive compounds, such as pectin, polyphenols and terpenes. The potential value of the waste orange peel has stimulated the search for extraction processes, alternative or complementary to landfilling or to the integral energy conversion. This study introduces controlled hydrodynamic cavitation processes, as a new route to the integral valorization of this by-product, based on simple equipment, speed, effectiveness and efficiency, scalability, and compliance with green extraction principles. Waste orange peel, in batches of several kg, was processed in more than 100 L of water, absent any other raw materials, in a device comprising a Venturi-shaped cavitation reactor. The extractions of pectin, endowed with a very low degree of esterification, polyphenols (flavanones and hydroxycinnamic acid derivatives), and terpenes (mainly d-limonene) were effective and fast (high yield, few min of process time), as well as the biomethane generation potential of the process residues was effectively exploited. The achieved results proved the viability of the proposed route to the integral valorization of waste orange peel, though wide margins exist for further improvements.
ARTICLE | doi:10.20944/preprints201907.0226.v1
Subject: Chemistry, Food Chemistry Keywords: Fry; boil; phenolic compounds; antioxidant capacity; extra virgin olive oil; Mediterranean vegetables
Online: 19 July 2019 (10:30:19 CEST)
Extra virgin olive oil, water, and water/oil mixture (W/O) were used to fry, boil and sautée Mediterranean vegetables. We determined the variations between unused and used water and oil for the contents of total (TPC) and individual phenolic compounds measured by HPLC, and the antioxidant capacity (AC) by DPPH, FRAP and ABTS methods. The highest TPC value was found in water used to boil tomato, whereas the lowest in the EVOO from the W/O used for boiling potatoes. The TPC decreased in the processed EVOO, whereas the water was enriched after boiling. After processing, the concentrations of phenols exclusive to EVOO diminished with differentiated behavior, from complete elimination of hydroxytyrosol and tyrosol after sautéeing and W/O boiling, to conservation of pinoresinol. The transfer of phenols such as chlorogenic, gallic, dihydroxybenzoic, hydroxybenzoic and hydroxyphenylacetic acids, as well as luteolin, apigenin and vanillic acid from the vegetable to the oil was frequent when eggplant, tomato and pumpkin were cooked. The cooking water was enriched in most of the phenols analysed, as the case of chlorogenic acid and phenols exclusive to EVOO after W/O boiling. The values of AC in the fresh oil decreased or were maintained after being used to cook the vegetables. With some exceptional increases in the oil used for frying (p<0.05). The cooking techniques were classified in decreasing order according to the AC as follows: raw>deep frying>sautéing>boiling. This pattern was more consistent with DPPH results (from potato, eggplant and pumpkin) than in those of ABTS (pumpkin) and FRAP (eggplant). The water fraction recovered from boiling was enriched in Trolox equivalents being higher when EVOO was added. Phenolic content and AC in the EVOO decreased after cooking Mediterranean Diet vegetables, whereas the water was enriched after the boiling processes, particularly when oil was included.
ARTICLE | doi:10.20944/preprints201905.0334.v1
Subject: Chemistry, Food Chemistry Keywords: antoxidants; bergamot; bioactive compound; biometrics; biomolecules; citrus bergamia risso; cloudy
Online: 28 May 2019 (10:50:32 CEST)
Reggio Calabria province (South Italy) is known for being almost the only area of cultivation of the bergamot fruit, grown principally for its essential oil, but today much studied for the health benefits of its juice. The biometrics and physico-chemical properties of the three (Citrus bergamia Risso) existing genotypes namely Castagnaro, Fantastico and Femminello were studied during fruit ripening from October to March. Castagnaro cv had the biggest and heaviest fruit during this harvest period. °Brix (7.9-10.0), pH (2.2-2.8) and Formol number (1.47-2.37 mL NaOH 0.1N/100mL) were shown to be influenced by both the genotype and by the harvest date. Titratable acidity (34.98-59.50 g/L) and Vitamin C (Ascorbic acid) (341-867 g/L) decreased during fruit ripening. The evolution of flavonoids such as neoeriocitrin, naringin, neohesperidin brutieridin and melitidin was studied both in bergamot juice and in the bergamot cloudy which is the aqueous extract of bergamot during fruit processing. Bergamot cloudy contained a higher quantity of flavonoids compared to the juice. This study gives important information regarding the cultivar and the harvest date for producers who want to obtain the highest juice quantity or the highest juice quality from the bergamot fruit.
ARTICLE | doi:10.20944/preprints201905.0303.v1
Subject: Chemistry, Food Chemistry Keywords: acacia; anthocyanins; cherry; color; model wine; oak; wood extracts
Online: 27 May 2019 (09:36:10 CEST)
There is a restricted knowledge about the potential impact of the use of different wood species on color and anthocyanin changes during the red wine aging process. This lack of knowledge is even greater when no oak wood species are used. Thus, the aim of this study was to carry out a comparative analysis of the impact of wood chip extracts from oak, acacia and cherry species on the chromatic characteristics and anthocyanins changes by the use of model wine solutions. In this context, several methodologies were used to quantified, color and anthocyanins changes during the aging time studied. The results indicated that the contact between wood chip extracts and grape skin isolated anthocyanin extracts induced a decrease of color intensity, particularly red color, and also the anthocyanin content in the different experimental model wine solutions studied. All chromatic modifications are potentially detected by human eyes because ΔE values were much higher than 3 CIELab units. These tendencies seems to be independent of the wood species used, but more pronounced for higher contact time between wood chip extracts and anthocyanins. The obtained results may contribute to a better understanding of the chromatic changes of red wines when aged in contact with different wood chips species.
ARTICLE | doi:10.20944/preprints201905.0048.v1
Subject: Chemistry, Food Chemistry Keywords: extruded cereals; flaxseed; amaranth; dietary fiber; extrusion-cooking
Online: 6 May 2019 (10:22:44 CEST)
The addition of flaxseed and amaranth on the physicochemical, functional and microstructural changes of instant-extruded cereals was evaluated. Six different mixtures were made with additions of amaranth (30%–50%) and flaxseed (10% and 15%) using maize grits and minor additives as supplementary ingredients and then extruded in a twin-screw extruder. The extrudates evaluated, had insoluble and soluble fiber contents increased with the proportion of amaranth and flaxseed. The mixture 4 (higher flaxseed content) presented highest soluble fiber percentage (1.9%). Extruded cereals had the lowest viscosity (<99.5 cp) and highest hardness values (5.2 N) whereas the dietary fiber content was highest. Fiber content increase, resulted in a higher water solubility index (WSI) (0.5) and decrease the water absorption index (WAI) (2.5). Amaranth and flaxseed incorporation increased crystallinity, resulting in a larger, and more compact laminar structure. Amaranth and flaxseed addition resulted in extruded cereals with acceptable physicochemical and functional properties.
Subject: Chemistry, Food Chemistry Keywords: waste cooking oil; volatiles; 1H NMR; mass spectrometry; prototype
Online: 16 April 2019 (11:19:15 CEST)
Samples of sunflower Waste Cooking Oils (WCOs) subjected to several cycles of frying were treated with water under four different combinations of temperature and pH. The variation of the chemical composition of the oil samples was monitored through headspace Solid-Phase Microextraction (HS-SPME) coupled with gas-chromatographic technique (GC), 1H NMR spectroscopy and ESI+ mass spectrometry measurements. The possibility to modify the chemical composition of the recycled vegetable oil by tuning the water treatment parameters was exploited for the designing of a mini-plant for the production of bio-lubricants. A full description of the proposed prototype is also reported.
Subject: Chemistry, Food Chemistry Keywords: antimicrobial activity; antiradical activity; chitosan; hydroxypropylmethylcellulose; lignin; pathogenic microorganisms; organosolv
Online: 25 March 2019 (11:40:11 CET)
The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. The polyphenol structure of lignin in addition to the presence of O-containing functional groups is potentially responsible for these activities. This study used DPPH assays to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. The scavenging activity (SA) of both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems was affected by the percentage of the added lignin: the 5% addition showed the highest activity and the 30% addition had the lowest. Both, scavenging activity and antimicrobial activity are depending on the biomass source showing the following trend: organosolv of softwood > Kraft of softwood > organosolv of grass. Testing the antimicrobial activities of lignins and lignin-containing films showed high antimicrobial activities against gram-positive and gram-negative bacteria at 35 °C and at low temperatures (0-7 °C). Purification of kraft lignin has a negative effect on the antimicrobial activity while storage has positive effect. The lignin release in the produced films affected the activity positively and the chitosan addition enhances the activity even more for both gram-positive and gram-negative bacteria. Testing the films against spoilage bacteria that grow at low temperatures revealed the activity of the 30% addition on HPMC/L1 film against both B. thermosphacta and P. fluorescens while L5 was active only against B. thermosphacta. In HPMC/lignin/chitosan films the 5% addition exhibited activity against both B. thermosphacta and P. fluorescens.
Subject: Chemistry, Food Chemistry Keywords: Electronic nose; apple; mildew; pattern recognition; artificial neural network; nondestructive examination
Online: 21 March 2019 (09:54:00 CET)
In this paper, PEN3 electronic nose was used to detect and recognize fresh and moldy apples (inoculated with Penicillium expansum and Aspergillusniger) taken Golden Delicious apples as model subject. Firstly, the apples were divided into two groups: apples only inoculated with different molds (Group A) and mixed apples of inoculated apples with fresh apples (Group B). Then the characteristic gas sensors of the PEN3 electronic nose that were most closely correlated with the flavor information of the moldy apples were optimized and determined, which can simplify the analysis process and improve the accuracy of results. Four pattern recognition methods, including linear discriminant analysis (LDA), backpropagation neural network (BPNN), support vector machines (SVM) and radial basis function neural network (RBFNN), were then applied to analyze the data obtained from the characteristic sensors, respectively, aiming at establishing the prediction model of flavor information and fresh/moldy apples. The results showed that only the gas sensors of W1S, W2S, W5S, W1W and W2W in the PEN3 electronic nose exhibited strong signal response to the flavor information, indicating were most closely correlated with the characteristic flavor of apples and thus the data obtained from these characteristic sensors was used for modeling. The results of the four pattern recognition methods showed that BPNN presented the best prediction performance for the training and validation sets for both the Group A and Group B, with prediction accuracies of 96.29% and 90.00% (Group A), 77.70% and 72.00% (Group B), respectively. Therefore, it first demonstrated that PEN3 electronic nose can not only effectively detect and recognize the fresh and moldy apples, but also can distinguish apples inoculated with different molds.
Subject: Chemistry, Food Chemistry Keywords: tree peony flowers; sugars and organic acids; amino acids; polyphenols; GC-MS; LC-MS
Online: 20 March 2019 (15:09:50 CET)
Tree peony flowers are traditional ornamental and medicinal materials in China. In this study, 23 tree peony flowers at a broad color spectrum were analyzed. Gas chromatography-mass spectrometer (GC-MS) revealed that tree peony flowers are rich in sugars and organic acids. Up to 18 amino acids were identified by liquid chromatography-mass spectrometer (LC-MS), including all essential amino acids, except for methionine. The majority of amino acids were significant positively correlated with each other and were significant negatively correlated with glucose, fructose and galactose. A total of 11 polyphenols were identified in these tree fresh peony flowers by LC-MS. There was a high consistency in grouping peony flowers by using sugars and organic acids and amino acids, which differed from that based on color components and polyphenols. Tree peony flowers are also rich in K, Ca, Mg and Fe. In together, peony flowers can be a good resource of health-promoting compounds.
ARTICLE | doi:10.20944/preprints201903.0119.v1
Subject: Chemistry, Food Chemistry Keywords: effervescence; bubbles; protein; yeast invertase; foamability; wine quality
Online: 11 March 2019 (08:04:48 CET)
The appearance of bubbles and foam can influence the likeability of a wine even before its consumption. Since foams are essential to visual and taste attributes of sparkling wines, it is of great importance to understand which compounds affect bubbles and foam characteristics. The aim of this work was to investigate the effect of interactions among proteins, amino acids, and phenols on the characteristics of foam in sparkling wines by using synchronous fluorescence spectroscopy techniques. Results has shown that several compounds present in sparkling wines influence foam quality differently, and importantly, highlighted how the interaction of those compounds might result in different effects on foam parameters. Amongst the results, mannoproteins were found to be most likely to promote foam and collar stability, while phenols were likely to increase the ratio of small bubbles and collar height in the foam matrix. In summary, this work contributes to a better understanding of the effect of wine compounds on foam quality as well as the effect of the interactions between those compounds.
ARTICLE | doi:10.20944/preprints201902.0023.v1
Subject: Chemistry, Food Chemistry Keywords: anchovy; omega-3; limonene; circular economy; fish processing waste; marine fishery discards
Online: 3 February 2019 (02:58:23 CET)
Fish oil rich in polyunsaturated omega-3 fatty acids is extracted in high yield from anchovy filleting waste using d-limonene as green biosolvent in a simple solid-liquid extraction performed by mechanically stirring and maceration followed by limonene removal via evaporation under reduced pressure. As limonene is renewably obtained from waste orange peel, this protocol establishes a circular bioeconomy method to obtain valued omega-3 extracts from biowaste available worldwide in several million t/year amount. The method closes the materials cycle and opens the route to full valorisation of an important biological resource so far mostly discarded as waste. Significant economic opportunities benefiting local communities, the ecosystem and public health are anticipated.
ARTICLE | doi:10.20944/preprints201901.0031.v1
Subject: Chemistry, Food Chemistry Keywords: Chagalapoli (Ardisia compressa), fermented beverage, phenolic compounds
Online: 3 January 2019 (14:37:19 CET)
Chagalapoli fruit (Ardisia compressa) is similar to Vaccinium myrtillus (berries) with high-polyphenol content. The objective of this study was to evaluate the physicochemical properties of Chagalapoli fruit and to determine the conditions for the preparation of a fermented beverage using Saccharomyces cerevisiae yeast, evaluating the impact on sensory properties. The fermentation process lasted 4 days at 27 °C, with absence of light and a fixed pH of 3.8. The phenolic contents obtained in samples according to chromatograms were 1.27 mg(EPI)/mL in filtered juice, 1.59 mg(EPI)/mL in filtered fermented beverage, 1.91 mg(EPI)/mL in partially filtered juice and 3.19 mg(EPI)/mL in partially filtered fermented beverage. An affective test was carried out to determine the sensory acceptability of the final product, evaluating the flavor, color and aroma parameters. The fermented beverage with the greatest preference on color and flavor attributes was the partially filtered fermented beverage.
ARTICLE | doi:10.20944/preprints201812.0163.v1
Subject: Chemistry, Food Chemistry Keywords: authenticity; chromatographic fingerprint; fatty acids; classification; linear discriminant analysis
Online: 13 December 2018 (08:43:49 CET)
The fatty-acid profiles of five main commercial pistachio cultivars, including Ahmad-Aghaei, Akbari, Chrok, Kalle-Ghouchi and Ohadi, were determined by gas chromatography: palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), oleic (C18:1), linoleic (C18:2), linolenic (C18:3) arachidic (C20:0) and gondoic (C20:1) acid. Based on the oleic to linoleic acid (O/L) ratio, a quality index was determined for these five cultivars: Ohadi (2.40) < Ahmad-Aghaei (2.60) < Kale-Ghouchi (2.94) < Chrok (3.05) < Akbari (3.66). Principal component analysis (PCA) of the fatty-acid data yielded three significant PCs, which together account for 80.0% of the total variance in the data set. A linear discriminant analysis (LDA) model evaluated with cross validation correctly classified almost all samples: the average percent accuracy for the prediction set was 98.0%. The high predictive power for the prediction set shows the ability to indicate the cultivar of an unknown sample based on its fatty-acid chromatographic fingerprint.
ARTICLE | doi:10.20944/preprints201812.0024.v1
Subject: Chemistry, Food Chemistry Keywords: extra-virgin olive oil adulteration; vegetables oils; triglycerides; fatty acids; linear discriminant analysis; principal component analysis
Online: 3 December 2018 (13:38:58 CET)
Nowadays, the fingerprinting methodologies of olive oils are dominated. They consider the entire analytical signal, which is acquired and recorded by the analytical instrument, directly from olive oil or isoleted fraction, i,e chromatogram. The shape and intensity of the recorded signal the instrumental fingerprint from the whole olive oil adulteration. Therefore, the methodolygy is based on the chemical composition (Fatty acids and Triglycerides compositions). However, Fatty acids composition as an indicator of purity suggests that linolenic acid content could be used as a parameter for the detection of extra virgin olive oil fraud with 5% of soybean oil. The adulteration could also be detected by the increase of the trans-fatty acid contents with 3% of soybean oil, 2% of corn oil and 4% of sunflower oil. The use of the ∆ECN42 proved to be effective in the Chemlali extra-virgin olive oil adulteration even at low levels: 1% of sunflower oil, 3% of soybean oil and 3% of corn oil. Therefore, compared to classical methods PCA and new approach of using LDA application could represent an alternative and innovative tool for faster and cheaper evaluation of extra-virgin olive oil adulteration.
ARTICLE | doi:10.20944/preprints201811.0548.v1
Subject: Chemistry, Food Chemistry Keywords: Persimmon, Diospyrus kaki Thunb., var. Rojo Brillante, astringent, carotenoids, carotenoid esters, HPLC-PDA-MS (APCI+), processing effects
Online: 22 November 2018 (14:26:40 CET)
Carotenoid and carotenoid esters profiles of peel, pulp and whole fruit tissues of astringent persimmon (Diospyrus kaki Thunb., var. Rojo Brillante) have been characterized in detail and quantified for the first time. Carotenoids were determined by HPLC-PDA-MS/MS (APCI+), using a reverse phase C30 column. A total of 38 carotenoids were identified and quantified, corresponding to 21 free carotenoids (13 xanthophylls and 8 hydrocarbon carotenes) and a total of 17 carotenoid esters. The qualitative profiles are very similar among tissues, differing only in the carotenoids concentration. The most important identified free xanthophylls were (all-E)-β-cryptoxanthin, (all-E)-antheraxanthin, (all-E)-lutein, (all-E)-zeaxanthin and (all-E)-violaxanthin . Hydrocarbon carotenoids found were (all-E)-β-carotene, (all-E)-α-carotene, (9Z)-β-carotene, (13Z)-β-carotene, (9Z)-α-carotene, and lycopene. The most abundant carotenoid esters were (all-E)-lutein-3-O-palmitate, (all-E)-zeaxanthin myristate, (all-E)-zeaxanthin palmitate and (all-E)-cryptoxanthin laurate. Processing by high pressures produced no regular effect on persimmon carotenoids and pasteurization affected negatively the content of all carotenoids from all studied persimmon tissues. This work will contribute to the development of scientific research about the bioaccessibity and bioavailabity of each individual free or esterified persimmon carotenoids in order to a better understanding of the carotenoid compounds impact in human health.
ARTICLE | doi:10.20944/preprints201811.0402.v1
Subject: Chemistry, Food Chemistry Keywords: chemical composition; smoothies; fruit blends; antioxidant properties; Moringa oleifera leaf; sensory evaluation
Online: 16 November 2018 (10:56:56 CET)
This study evaluated the impact of the level of supplementation of Moringa oleifera leaves on the nutritional (proximate, mineral and vitamin content) as well as on the antioxidant capacities of smoothies made from a blend of pineapple, banana and apple. The beverage (smoothies) were supplemented with Moringa oleifera leaves at 1.5, 3.0 and 4.5% levels and evaluated for proximate, antioxidant (ferric reducing antioxidant power, FRAP and 2,2-Diphenyl-1-picryhydrazy, DPPH), mineral, vitamin, physicochemical and quality acceptability. The results showed that the moisture content of the beverage ranged between 49.24 – 78.62%, total ash: 1.01 – 9.71, crude fiber: 5.14 – 9.39%, crude fat: 0.72 – 1.86%, crude protein: 5.47 – 19.37% and carbohydrate: 3.65 – 16.99%. Calcium (12.03 -15.53) and potassium (17.22 -25.38) were the predominant mineral elements when compared to magnesium (1.51 – 3.05) mg/L. The vitamin contents ranged between 2.5 – 10.8 and 0.15 – 0.93 mg/L for vitamin C and E, respectively. Total phenolic contents ranged between 4.68 – 6.18 mg/ml while the total flavonoid contents ranged between 0.01 – 0.14 mg/ml. The radical scavenging abilities (DPPH) of the samples ranged between 16.05 – 88.77% while the ferric reducing antioxidant power (FRAP) ranged between 0.38 – 7.36 mg/ml. The brix values showed high sugar contents (15 – 18%) while the pH results showed that the sample was almost neutral at a range between 6.3 and 6.5. The overall quality (sensory) acceptability of the different quality parameters evaluated indicated that the control sample was more preferred. While supplementation with Moringa oleifera leaves significantly affected the sensory parameters, its addition nevertheless offers a potential avenue to obtain additional nutrients besides its improved antioxidative properties.
ARTICLE | doi:10.20944/preprints201811.0093.v1
Subject: Chemistry, Food Chemistry Keywords: Wild fruits, phytochemicals, malnutrition and health
Online: 5 November 2018 (09:15:58 CET)
Widely consumed forest fruits in Gabon, were analyzed for nutrient and bioactive compositions and their potential contributions to meeting the nutrient requirements of consumers. Edible pulps of Panda oleosa, Gambeya lacourtiana and Poga oleosa contained substantial amounts of bioactive compounds; flavonoids (13.5–22.8 mg/100g), proanthocyanins (2.4–7.6 mg/100g), polyphenols (49.6-77.3 mg/100g) and vitamin C (6.7–97.7 mg/100g). The highest content of β-carotene (76.6 µg/100g) was registered in fruits of Pseudospondias longifolia. The fruits of P. oleosa had the highest essential minerals Fe, Zn and Se. If a child aged 1 to 3 years consumed about 200g or if a non-lactating and non-pregnant woman consumed 300g of P. oleosa, A. lepidophyllus, G. lacourtiana, P. longifolia and P. oleosa, they could obtain substantial RDI ranging between 20-100% for energy, vitamins C and E, iron, magnesium, iron and zinc. Forest fruits can considerably contribute towards the human nutrient requirements. Based on the results of this study, forest foods should be considered in formulating policies governing food and nutrition security in Gabon.
REVIEW | doi:10.20944/preprints201811.0056.v1
Subject: Chemistry, Food Chemistry Keywords: white wine; volatile compounds; sensorial characteristics; oak; alternative woods; barrels; chips
Online: 2 November 2018 (12:40:47 CET)
Ageing wine is a commonly practice used in winemaking since the quality and sensory profile increase due to the extractable compounds coming from wood by means of barrels or chips. The quantitative and qualitative compounds from wood depend on the species, its origins and the treatments applied in cooperages. Traditionally, oak wood species are most often used in cooperage, specifically Quercus alba, Known as American oak and Q. robur and Q. petraea both known as French oak. However, although this stage is very common for red wines, its use is still restricted in the case of white wines. However, this topic is particularly interesting, since due to the sensorial benefits of wood contact, the option for ageing white wines in barrels or chips is increasingly and widely chosen by winemakers. This review compiles the novel strategies applied to white wines by means of wood contact in the last years with the aim to increase wine quality and sensorial features.
ARTICLE | doi:10.20944/preprints201811.0003.v1
Subject: Chemistry, Food Chemistry Keywords: coffee; acrylamide; furfuryl alcohol; 5-hydroxymethylfurfural; risk assessment
Online: 1 November 2018 (18:35:15 CET)
The three heat-induced coffee contaminants acrylamide, furfuryl alcohol (FA) and 5-hydroxymethylfurfural (HMF) were analyzed in a collective of commercial samples as well as in Coffea arabica seeds roasted under controlled conditions from very light Scandinavian style to very dark Neapolitan style profiles. Regarding acrylamide, average contents in commercial samples were lower than in a previous study in 2002 (196 compared to 303 µg/kg). The roasting experiment confirmed the inverse relationship between roasting degree and acrylamide content, i.e. the lighter the coffee the higher the acrylamide content. However, FA and HMF were inversely related to acrylamide and found in higher contents in darker roasts. Therefore, mitigation measures must consider all contaminants and not be focused isolatedly on acrylamide, specifically since FA and HMF are contained in much higher contents with lower margins of exposure compared to acrylamide.
ARTICLE | doi:10.20944/preprints201810.0398.v1
Subject: Chemistry, Food Chemistry Keywords: craft beer; polyphenols; bitterness; preference; sensory attributes
Online: 18 October 2018 (05:09:01 CEST)
The craft beers are outlined as a distinctively flavored, brewed and distributed regionally, using top-fermenting (ale) yeast, bottom-fermenting (lager) yeast or spontaneously fermentation. Craft beers are largely consumed and produced in Brazil and presents great level of polyphenols, which would affect the consumer’s preference. In this way, we analyzed the relation between polyphenols, bitterness and composition of main different styles of craft beers and the consumer´s preference. Six different styles were analyzed according its polyphenol content, bitterness, chemical composition, sensory profile and preference. For preference, a panel with 62 non-trained assessors was used. For sensory profile, the quantitative descriptive analysis was performed, using expert assessors (n = 8). The preferred style was Classic American Pilsner and the style less preferred was Standard American Lager. The craft beer more preferred showed a decreased bitterness (9.52), polyphenol content (0.61 mg EAG/mL), total solids (6.75 ºBrix) and turbidity (7.27 NTU). This beer exhibited reduced sensory notes of malty, fruity, smoked, hoppy and phenolic, but a higher perception of floral, sweet and yeast notes. The bitter attribute has a reduced perception. This study advances understanding the sensory profile and complexity of craft beers styles from Southern Brazilian.
ARTICLE | doi:10.20944/preprints201810.0195.v1
Subject: Chemistry, Food Chemistry Keywords: pounded yam; cocoyam; machine; panelist; texture; Yorubas; Nigeria
Online: 10 October 2018 (03:38:37 CEST)
Pounded yam eaten with any type of soup is a delicacy eaten by Nigerians. It is manually prepared by pounding yam, cocoyam or combination with mortar and pestle. Preparation takes 30-45 mins. Researches on the improvements have taken place to reduce the heavy burden on the pounded yam preparation. One of the efforts made is the fabrication of pounding machine from the Department of Engineering, Federal College of Agriculture, Akure, Nigeria. The aim of this study is to carry out the organoleptic analysis of pounded yam produced from the fabricated machine. A ten-man panelist was used to determine the organoleptic analysis of the pounded yam in terms of the appearance, taste, colour, odour and texture. The panelists were scored with a class of quality grading: 22.6-25.0 (excellent), 20.2-22.5 (good), 18.2-20.1 (satisfactory), 16.2-18.1 (less satisfactory), and <15.2 (unsatisfactory). Also, sensory attributes were scored as 1= unsatisfactory, 2= less satisfactory, 3= satisfactory, 4=good, and 5= excellent. The results were statistically analysed. From the results it was found that the mean results of appearance, colour, odour, taste, and texture were 4.55, 4.43, 4.15, 4.32, and 4.08 respectively. Coefficients of variation (%) were 16.89, 17.80, 21.65, 15.67, and 24.40. The Skewness of the parameters was in negative, while only odour has its Kurtosis in negative form (-0.37). All the panelists rated the appearance (19-24%) of all the samples high above all other parameters. The Pearson Coefficient of Correlation and Principal Component Analysis showed elements of relationships between the parameters. In conclusion, the machine pounded yam was scored above satisfactory, which means the fabricated machine was efficient.
ARTICLE | doi:10.20944/preprints201810.0113.v1
Subject: Chemistry, Food Chemistry Keywords: Sea Squirts; Metabolites; GC-MS; Anti-bacterial; Zika vector; larvicidal
Online: 6 October 2018 (11:18:31 CEST)
In this present study, we conducted untargeted metabolic profiling using Gas Chromatography-Mass Spectrometry (GC-MS) analysis of ascidian Didemnum bistratum to assess the chemical constituents by searching in NIST library with promising biological properties against anti-bacterial and Zika virus vector mosquitocidal Properties. Metabolites, steroids and fatty acids are abundant in crude compounds of ascidian D. bistratum and showed potential zone growth inhibition against bacterial strains Kluyvera ascorbate (10 mm). The active crude compounds of D. bistratum exhibited prominent larvicidal activity against the Zika vector mosquitoes of Aedes aegypti and Cluex quinquefasciatus (LC50 values of 0.4436 to 2.23 mg/mL). The findings of this study provide a first evidence of the biological properties exhibited by D. bistratum extracts, thus increasing the knowledge about the Zika virus vector mosquitocidal properties of ascidian. Overall, ascidian D. bistratum are promising and biocontrol or eco-friendly tool against A. aegypti and C. quinquefasciatus with prospective toxicity against non-target organisms.
ARTICLE | doi:10.20944/preprints201809.0432.v1
Subject: Chemistry, Food Chemistry Keywords: infrared spectroscopy; diffuse reflectance infrared Fourier transform spectroscopy; ion-exchange resin; drinking water
Online: 21 September 2018 (08:29:11 CEST)
Infrared spectroscopy is an effective method for the determination of compositions and concentrations of liquids, with advantages of fast response, no-sampling, flexible in use and is able for on-line monitoring. However, for trace substances in drinking water, such as nitrates and heavy metals, infrared spectroscopy is not sensitive enough for the quantitative and qualitative measurement. In this study, we improved the sensitivity of infrared spectroscopy for nitrite determination by developing an ion-exchange-enhanced diffuse reflectance spectroscopy, which consist of an accessory based on ion-exchange resin for enrichment and a FTIR spectrometer for measurement. Using this method, the limit of detection for nitrate is 1.7 mg/L, which is enough for drinking water sensing. We also verified the quantitative measurement ability of the method. Furthermore, the limit of detection and quantitative measuring range could be adjusted by changing the mass of resin and adsorption time. This study demonstrated the method can be used to detect trace nitrites in drinking water, can be applied in the field, and is sensitive, rapid, and inexpensive with a wide dynamic range.
REVIEW | doi:10.20944/preprints201809.0422.v1
Subject: Chemistry, Food Chemistry Keywords: LDL-oxidation; DNA-damage; antioxidant vitamins; oxidative stress
Online: 20 September 2018 (16:53:42 CEST)
Radical oxygen species formed in human tissue cells by many endogenous and exogenous pathways, cause extensive oxidative damage, which has been linked to various human diseases. This review paper provides an overview of lipid peroxidation and focuses on the free-radicals initiated processes of LDL oxidative modification and DNA oxidative damage, which are widely associated to the initiation and development of atherosclerosis and carcinogenesis, respectively. The article subsequently provides an overview of the recent human trials or even in vitro investigations on the potential of natural antioxidant compounds (such as carotenoids, vitamins C and E) to monitor LDL and DNA oxidative changes.
ARTICLE | doi:10.20944/preprints201809.0414.v1
Subject: Chemistry, Food Chemistry Keywords: Sweet cherry; Anthocyanins; Non-coloured phenolics; Antioxidant activity; Erythrocytes protection; Caco-2 cells.
Online: 20 September 2018 (14:23:18 CEST)
This study aimed to compare three different extracts of Saco sweet cherry, namely non-coloured fraction, coloured fraction and total extract concerning phenolic composition, antioxidant and antidiabetic potential, erythrocytes’ protection and effects on Caco-2 cells. A total of 22 phenolic compounds were identified by LC-DAD. Hydroxycinnamic acids were the most predominant in both non-coloured fraction and total extract, while cyanidin-3-O-rutinoside was the main anthocyanin found in the coloured fraction. The total extract was the most effective against DPPH, nitric oxide and superoxide radicals, and in the inhibition of α-glucosidase enzyme. Finally, the protective effect of the extracts to prevent oxidative damage in human erythrocytes was assessed. The coloured fraction revealed the best activity against hemoglobin oxidation and hemolysis. Regarding to Caco-2 cells, the coloured extract exhibited the most cytotoxic effects, while the total extract was the most efficient in protecting these cells against oxidative damage induced by t-BHP.
ARTICLE | doi:10.20944/preprints201809.0386.v1
Online: 19 September 2018 (13:59:33 CEST)
Menaquinone-7 is a member of the vitamin K family whose interest has considerably increased over the last decade due to its beneficial role in human health mainly in respect to bone and cardiovascular health leading to a growing use in different nutritional supplement. Menaquinone-7 can be produced by synthesis or fermentation and its purity profile can differ depending on methodologies and extraction procedures. Finished formulation show a large heterogeneity of purity profiles as well as frequent discrepancies in the nominal content compared to the actual title. In the present study we compared purity profiles of different raw material and we related them to stability assay in normal (12months/25°C/60%RH) and accelerated conditions (6 months/40°C/75% RH) in order to test their performance in presence of different common excipients. Results show that higher purity profile correlates with enhanced stability and this could explain title discrepancies found in finished products found on the market worldwide.
ARTICLE | doi:10.20944/preprints201809.0338.v1
Subject: Chemistry, Food Chemistry Keywords: Ocimum spp.; essential oil; aromatic profiles; Thai food
Online: 18 September 2018 (09:47:32 CEST)
The research objectives of this study are to analyse the volatile compositions of different basil types available in Thai markets and to descriptively determine their aromatic qualities. Essential oils were hydro-distillated from fresh leaves of 2 Holy basil (Ocimum sanctum) varieties namely, white and red and other basil species, including Tree basil (O. gratissimum), Sweet basil (O. basilicum var. thyrsiflorum) and Lemon basil (O. citriodorum). Oil physicochemical characteristics and volatile chromatograms from Gas Chromatography-Mass Spectrometry (GC-MS) were used to qualitatively and quantitatively describe the chemical compositions. Methyl eugenol, estragole and eugenol were among the major chemicals found in the essential oils of these basil types. Classification by Principal Component Analysis (PCA) advised that these Ocimum spp. samples are grouped based on either the distinctive anise, citrus aroma (estragole, geranial and neral) or spice-like aroma (β-methyl eugenol, caryophyllene and α-cubebene). The essential oil was also used for descriptive sensorial determination by five trained panelists, using the following developed terms: anisic, citrus, herb, spice, sweet and woody. The panelists were able to differentiate essential oil of white Holy basil from red Holy basil based on the intensity of the anisic attribute, while the anise and citrus scents were detected as dominant in the Lemon basil, Tree basil and Sweet basil essential oils. The overall benefit from this research was the elucidation of aromatic qualities from Thai common Ocimum species in order to assess their potential as the raw materials for future food research and development.
ARTICLE | doi:10.20944/preprints201809.0231.v2
Online: 17 September 2018 (10:35:49 CEST)
In this work, nine fruits cultivated in the northern Amazon were studied: abiu, acerola, araçá, bacupari, biribá, caçarí, fruta-do-conde, graviola and taperebá, with the objective of carrying out a bromatological and nutritional study of the pulps of fruits studied. Of all of them, are the pulps of graviola (76.83 ± 0.02 kcal 100 g-1) bacupari (76.83 ± 0.02 kcal 100 g-1) and fruta-do-conde (46.66 ± 0.02 kcal 100 g-1). Among the macronutrients, the high concentration of potassium stands out, especially in the graviola (541.16 ± 0.24 mg 100 g-1) and the biribá (468.21 ± 0.13 mg 100 g-1). Among the micronutrients, iron concentrations are representative for araçá pulp (3.04 ± 0.02 mg 100g-1), abiu is rich in zinc (3.71 ± 0.02 mg 100 g-1) and manganese (6.61 ± 0.11 mg 100 g-1). The presence of cobalt at the level of traces in some of the pulps studied stands out. The Pearson correlation coefficient was evaluated, as well as the statistical treatment by multivariate analysis PCA to establish the correlation between the variables studied.
ARTICLE | doi:10.20944/preprints201809.0274.v1
Subject: Chemistry, Food Chemistry Keywords: rice bran; rice genes; rice cultivars; metabolic pathway; metabolomics
Online: 15 September 2018 (19:34:43 CEST)
Rice (Oryza sativa L.) processing yields ~60 million metric tons of bran annually. Rice genes producing bran metabolites of nutritional and human health importance were assessed across 17 diverse cultivars from seven countries using non-targeted metabolomics and resulted in 378-430 metabolites. Gambiaka cultivar had the highest number and Njavara had the lowest number of metabolites. The 71 rice bran compounds of significant variation by cultivar included 21 amino acids, seven carbohydrates, two metabolites from cofactors and vitamins, 33 lipids, six nucleotides, and two secondary metabolites. Tryptophan, -ketoglutarate, γ-tocopherol/β-tocopherol and γ-tocotrienol are example bran metabolites with extensive cultivar variation and genetic information. 34 rice bran components that varied between cultivars linked to 535 putative biosynthetic genes using to the OryzaCyc 4.0, Plant Metabolic Network database. Rice genes responsible for bran composition with animal and human health importance is available for rice breeding programs to utilize in crop improvement.
ARTICLE | doi:10.20944/preprints201809.0045.v1
Subject: Chemistry, Food Chemistry Keywords: bottle color, shelf life, Vitis vinifera L., quality control
Online: 3 September 2018 (15:25:23 CEST)
The objective of this study was to evaluate the evolution of the Syrah red and sparkling Moscatel wines stored for 12 months in green, amber and clear bottles. The phenolic compounds profile and antioxidant activity in vitro were determined. Commercial wines were bottled in an automatic filling machine, stored and analyzed every three months for one year. Several phenolic compound families were quantified through reversed-phase high performance liquid chromatography (RP-HPLC) coupled to diode-array detection (DAD) and fluorescence detection (FD). The different bottle colors studied did not influence the evolution of the sparkling Moscatel and Syrah red wines, since the main variations obtained were related to storage time. The main changes were observed in the Syrah wine, where storage time was associated with an increase in hue (h*), decrease in catechins, increase in procyanidins and, most notably, a decrease in the anthocyanin malvidin 3-glucoside. In general, the wines showed good stability in relation to the antioxidant activity in vitro.
ARTICLE | doi:10.20944/preprints201808.0322.v1
Subject: Chemistry, Food Chemistry Keywords: malolactic fermentation; coinoculation; diacetyl; esters; aromatic compounds; grape wine
Online: 18 August 2018 (06:00:30 CEST)
We examined the effects of different malolactic bacteria fermentation techniques, including a spontaneous process – a variant with a high risk of undesirable metabolites – on the bioconversion of aromatic compounds in cool-climate grape wines. During three wine seasons, red and white grape wines were produced by three different methods of malolactic fermentation induction: coinoculation, sequential inoculation, and spontaneous malolactic fermentation. Volatiles (diacetyl and the products of its metabolism, as well as selected ethyl fatty acids esters) were extracted by solid phase microextraction. Compounds were identified with multidimensional gas chromatograph GCxGC-ToFMS with ZOEX cryogenic (N2) modulator. Sensory evaluation of the wines was also performed. We found, that the fermentation-derived metabolites examined in this study were affected by the malolactic bacteria inoculation regime. Quantitatively, ethyl lactate, diethyl succinate and ethyl acetate dominated as esters with the largest increase in the concentration. The total concentration of ethyl esters was highest for the coinoculation scenario. Whereas the highest concentration of diacetyl was noted for the spontaneous processes. A controlled malolactic fermentation, especially using the coinoculation technique, can be proposed as a safe and efficient enological practice for producing quality, cool-climate grape wines enriched with fruity, fresh and floral aromas.
COMMUNICATION | doi:10.20944/preprints201808.0126.v2
Subject: Chemistry, Food Chemistry Keywords: hot foods; temperature; esophageal cancer; thermosensing; sensory thresholds; methodological study
Online: 9 August 2018 (12:50:40 CEST)
Epidemiological studies indicate an increased risk of cancer from the consumption of very hot foods and beverages. The International Agency for Research on Cancer (IARC) has already recommended threshold values for the maximum drinking temperature of very hot beverages. The contact time and the contact temperature are decisive for the risk of injury when hot media come into contact with human skin. However, measuring the contact temperature is not easily possible in practice. In the present study, a numerical simulation based on the solution of the heat conduction equation was initially used to investigate whether and for what period of time a constant contact temperature is to be expected under oral conditions. For small circular 3-cm food samples (e.g., cooked potatoes) with 2.5 mm thickness in contact with the tongue, the simulation results in a constant contact temperature of 10 s before cooling. With a thickness of 0.5 mm, the contact temperature is only maintained 1 s. Hot beverages, which spread as a thin film and thereby increase their surface area, can therefore be consumed at higher temperatures than solid foods. Furthermore, a simple test technique with a "measuring spoon" was developed. A hot sample is placed on the tongue. Orientating measurements were used to determine which contact temperature was considered to be just comfortable for any period > 10 s and for which period of less than 10 s it was still just bearable. The contact temperature, which was still perceived as tolerable for periods > 10 s, was 46.5 °C. The time spans for the higher contact temperature 48 °C were between 2 and 4 s and for 49 °C between 1 and 2 s. The course of the contact temperatures determined in the experiment over time allows to calculate the corresponding threshold values of consumption temperatures for various foods. Consumption temperatures of about 56 °C for potatoes and 60 °C for cheese are still perceived as tolerable. In view of the fact that the contact temperature is obviously the determining factor for the risk of injury from burns in the oral cavity in addition to the contact time, it makes sense to reference threshold values to the contact temperature rather than to the surface or consumption temperature of a food product, which is current customary practice. If this contact temperature is defined as a threshold value, the surface or consumption temperature for any other food can be calculated.
REVIEW | doi:10.20944/preprints201808.0111.v1
Subject: Chemistry, Food Chemistry Keywords: enabling technologies; pilot reactors; ultrasound; hydrodynamic cavitation; polyphenols; grape pomace; olive leaves.
Online: 6 August 2018 (10:18:35 CEST)
We herein provide an overview of the most recent multidisciplinary process advances that have occurred in the food industry as a result of changes in consumer lifestyle and expectations. The demand for fresher and more natural foods is driving the development of new technologies that may efficiently operate at room temperature. Moreover, the huge amount of material discarded by the agro-food production chain lays down a significant challenge for emerging technologies that can provide new opportunities by recovering valuable by-products and creating new applications. Aiming to design industrial processes, there is a need of pilot scale plants such as the “green technologies development platform” that was established by the authors. The platform is made up of a series of multifunctional laboratories that are equipped with non-conventional pilot reactors developed in direct collaboration with partner companies in order to bridge the enormous gap between academia and industry via the large-scale exploitation of relevant research achievements. Selected key, enabling technologies for process intensification make this scale-up feasible. We make use of two selected examples, the grape and olive production chains, to show how cavitational reactors, which are based on high-intensity ultrasound and rotational hydrodynamic units, can assist food processing and the sustainable recovery of waste to produce valuable nutraceuticals as well as colouring and food-beverage additives.
ARTICLE | doi:10.20944/preprints201807.0550.v1
Subject: Chemistry, Food Chemistry Keywords: Mercury, Pelagic Fish, Direct Mercury Analyzer, Mediterranean Sea, Tolerable Weekly Intake
Online: 27 July 2018 (17:23:58 CEST)
Mercury (Hg) fish and seafood contamination is a global concern and needs worldwide sea investigations in order to protect consumers. The aim of this study was to investigate the Hg concentration by means of a rapid and simple analytical technique with direct Mercury Analyzer (DMA-80) in pelagic fish species, Tetrapturus belone (spearfish), Thunnus thynnus (tuna) and Xiphias gladius (swordfish) caught in the Mediterranean Sea. Hg contents were evaluated also in Salmo salar (salmon) as pelagic fish not belonging to the Mediterranean area. The results obtained were variable ranging between 0,015-2,562 mg kg-1 for T. thynnus specie, 0,477-3,182 mg kg-1 for X. gladius, 0,434-1,730 mg kg-1 for T. belone and 0,004-0,019 mg kg-1 for S. salar, respectively. The total Hg tolerable weekly intake (TWI) and % tolerable weekly intake (TWI%) values according to the European Food Safety Authority (EFSA) were calculated. The results highlighted that the pelagic species caught in the Mediterranean Sea should be constantly monitored due to their high Hg contents as well as their TWI and TWI% with respect to S. salar samples.
ARTICLE | doi:10.20944/preprints201807.0470.v1
Subject: Chemistry, Food Chemistry Keywords: Arthrospira platensis; carotenoids; natural pigments; spirulina powder; C-phycocyanin; antioxidant activity
Online: 25 July 2018 (06:19:11 CEST)
Arthrospira platensis is the widely available source of spirulina and contains distinctive natural pigments including carotenoids and C-phycocyanin (C-PC). In this study, the major carotenoid and C-PC contents were determined in seven commercially available spirulina powder products and laboratory-prepared A. platensis trichomes (AP-1) by an LC-DAD method and a UV-Visible spectrometry, respectively. The correlation of these two pigment content levels with Hunter color coordinates and antioxidant activity was also evaluated. The L* value failed to show a significant correlation with pigment content, but a positive correlation was observed between a* values and the contents of total carotenoid and C-PC. As b* values decreased, the total carotenoid and C-PC contents increased. AP-1 exhibited the highest content of total carotenoids, chlorophyll a and C-PC, and antioxidant activities among the samples. This observation could be related to degradation of these pigments during the mass production process. The carotenoid profiles suggested that the commercial spirulina powders originated from two different sources, A. platensis and A. maxima. Total carotenoid and C-PC content exhibited positive significant correlations with antioxidant activities measured by DPPH and ABTS assays. These results provide a strong scientific foundation for the establishment of standards for the commercial distribution of quality spirulina products.
ARTICLE | doi:10.20944/preprints201807.0396.v1
Subject: Chemistry, Food Chemistry Keywords: Wine; DPPH; FRAP; Hippophae rhamnoides L. leaves; sulphur dioxide
Online: 21 July 2018 (14:41:04 CEST)
This study evaluated the influence of the addition of increasing quantities of Hippophae rhamnoides L. leaves (HRL) on the radical scavenging activity, main oenological parameters and organoleptic characteristics of three white wines made from moschofilero and one white wine made from riesling grapes respectively. Radical Scavenging activity, reducing power, total phenol content (TPC) and color intensity increased in a linear manner in relation to HRL treatments. Indicatively the addition of 0.8 g/L of HRL increased the radical scavenging activity as determined via the inhibition of the DPPH radical from 23.2 to 58.4% in comparison to the initial values. Equally the reducing power as determined by the FRAP assay increased from 34.5 to 82.3%, TPC increased from 12.3 to 26.8% and the color intensity increased from 39-50% . The main oenological attributes examined, remained unchanged after the HRL addition. The addition of up to 0.4 g/L of HRL did not have a major impact on the organoleptic characteristics of the wines tasted whereas concentrations higher than 0.8 g/L were not considered beneficial. Results denote that the addition of Hippophae rhamnoides L. leaves to white wines contributes positively to the overall antioxidant capacity and could be used as an antioxidant agent in wines vinified in the absence of sulphur dioxide.
ARTICLE | doi:10.20944/preprints201807.0394.v1
Subject: Chemistry, Food Chemistry Keywords: reduced-alcohol wine; solid-phase microextraction; gas chromatography; chemometrics
Online: 21 July 2018 (12:47:05 CEST)
The important sampling parameters of a headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) procedure, extraction temperature, extraction time and sample volume were optimized to quantify 23 important impact odorants in reduced alcohol red and white wines. A three-factor design of Box-Behnken experiments was used to determine optimized sampling conditions for each analyte, and a global optimized condition at every ethanol concentration of interest determined using a desirability function that accounts for a low signal response for compounds. Shiraz and Chardonnay wines were dealcoholized from 13.7 and 12.2% v/v ethanol respectively, to 8 and 5% v/v, using a commercially available membrane-based technology. A sample set of the reduced alcohol wines were also reconstituted to their natural ethanol level to evaluate the effect of ethanol content reduction on volatile composition. The three-factor Box-Behnken experiment ensured an accurate determination of the headspace concentration of each compound at each ethanol concentration, allowing comparisons between wines at varying ethanol levels to be made. Overall, the results showed that the main effect of extraction temperature was considered the most critical factor when studying the equilibrium of reduced alcohol wine impact odorants. The impact of ethanol reduction upon the concentration of volatile compounds clearly resulted in losses of impact odorants from the wines. The concentration of most analytes decreased with dealcoholization compared to that of the natural samples. Significant differences were also found between the reconstituted volatile composition and 5% v/v reduced alcohol wines, revealing that the dealcoholization effect is the result of a combination between the type of dealcoholization treatment and reduction in wine ethanol content.
ARTICLE | doi:10.20944/preprints201807.0267.v1
Subject: Chemistry, Food Chemistry Keywords: Filuferru; spirit; distillation; grape marc; volatile compounds; copper; trace elements; GC-MS; ICP-MS; PCA
Online: 16 July 2018 (09:23:20 CEST)
Traditional Filuferru is an ancient spirit from Sardinia, Italy, usually obtained from the distillation of wine or grape marc. In this contribution, the results of the first chemical characterization of a wide number of craft Filuferru samples has been accomplished in terms of evaluation of the alcoholic strength, qualitative and quantitative GC-MS analysis of the volatile composition of the distillate, and its trace element composition by means a ICP-MS method. Both instrumental methods have been validated and applied on 21 craft samples of Filuferru, whereas one sample of commercial distillate has been analyzed for comparison purposes. Alcoholic strength ranged between 41.0 and 62.4% (v/v). Sixty volatile compounds were identified and ten of them have been quantified. Analogies and differences with Grappa (i.e. the Italian distilled spirit most close to Filuferru) have been highlighted in the qualitative and quantitative profile of this matrix. Often meaningful amounts of acetaldehyde, ethyl acetate, dietyl acetal and acetic acid were measured. Elemental analysis, performed on toxic, non-toxic elements and oligoelements, 18 in total, revealed a wide variability of concentrations in both analytes and samples. High concentrations of Cu are sometimes evidenced, likely caused by losses from the distillation apparatus. The principal components analysis (PCA) allowed the differentiation of the ten volatile compounds quantified in two groups: the former, described mainly by PC1, constituted by acetic acid, ethyl acetate, dietyl acetal and acetaldehyde, and the second, described by PC2, constituted by 1-propanol, 2-methyl-1-propanol, the two coeluiting isomers 2-methyl-1-butanol and 3-methyl-1-butanol,1-hexanol, 2-phenylethanol and 2,3-butanediol. Data obtained may be useful in order to establish a regulation for the production of high-quality traditional Filuferru from Sardinia.
ARTICLE | doi:10.20944/preprints201804.0105.v1
Subject: Chemistry, Food Chemistry Keywords: DRS dielectric relaxation; DSC differential scanning calorimetry; SMP skim milk powder; boundary curves
Online: 9 April 2018 (10:22:24 CEST)
This paper describes the dielectric relaxation spectroscopy (DRS) method for obtaining glass transition temperature and the onset of crystallinity of skim milk powder (SMP). The methodology consists of exposing SMP samples to numerous constant temperatures, T, and water activities, aw, and measuring the relaxation time. Measurements are based on changes in the loss-tangent height at its peak frequency. Glass transition times are identified at peaks in the loss-tangent height versus time curve and the onset of crystallinity times are identified when the loss-tangent height collapses. The analysis leads to two boundary curves: glass transition Tg, aw curve and the onset of crystallinity Tc, aw curve. They separate the SMP stable (long shelf life) and unstable (short shelf life) regions. Two curve fitting algorithms were developed for (a) aw2, tg curve where tg is the time to glass transition and aw2, tc curve where time tc is the time to onset of crystallinity and (b) Tg, aw and Tc, aw boundary curves. Finally, the DRS data are compared to differential scanning calorimetry (DSC) results.
ARTICLE | doi:10.20944/preprints201804.0073.v1
Subject: Chemistry, Food Chemistry Keywords: Rossa da inverno sel. Rojo Duro onion cultivar; geographical origin; amino acids content; HPLC analysis; statistical evaluations; food traceability
Online: 6 April 2018 (09:04:47 CEST)
In the frame of a broader project, we were interested at comparing the amino acid profile in a specific variety of onion, Rossa da inverno sel. Rojo Duro, produced in two different Italian sites: Cannara (Umbria region) and Imola (Emilia Romagna region). In both places, onions were cultivated and harvested in the same way, and irrigated by water sprinkler method. A further group of Cannara onions, growth by microirrigation, was also evaluated. After the extraction of free amino acid mixture from onion samples, an ion-pairing RP-HPLC method allowed the separation and the evaporative light scattering detection of almost all underivatized proteinogenic amino acids. However, only the peaks corresponding to Leu, Phe, Trp, were present in all the investigated samples and unaffected from matrix interfering peaks. The application of the beeswarm/box plots with the ANOVA/TukeyHSD statistical approach revealed a content of Leu and Phe markedly influenced by the geographical origin of the onions, while not by the irrigation procedure. The developed HPLC method was validated in terms of specificity, linearity, LOD and LOQ, accuracy and precision, before the quantitative assay of Leu, Phe and Trp in the onion samples. Although further studies are necessary, these preliminary findings can represent a good starting point for considering the quantity of specific amino acids in the Rossa da inverno sel. Rojo Duro variety as a fingerprint of its geographical origin. In principle, the developed approach might be applied to other onion varieties, thus contributing to their characterization and traceability, also contributing to limit commercial frauds.
ARTICLE | doi:10.20944/preprints201803.0111.v1
Online: 15 March 2018 (03:50:35 CET)
Onion (Allium cepal L.) is a major commercial vegetable crop grown in almost all parts of the world. In Ethiopian the postharvest loss of onion bulb crop was estimated to be 50% during the production season. So to reduce this postharvest loss of onion bulb determining and employing appropriate storage conditions play an important role. Appropriate storage condition reduces the physiological quality which intern reduces the physicochemical and phytochemical properties of onion. In this study physicochemical and phytochemical properties of onion bulb were investigated under different storage temperature. Onion bulbs were stored at three different temperatures the following quality attributes of onion bulb like glucosidase content, pyruvic acid, flavonoid, dry matter and sugar content were determined for storage period of six months. Quality deterioration of onion bulb was higher at storage temperature of 25 °C while storage temperature 5 °C was found an ideal condition with keeping the quality of onion bulb acceptable. In all the three storage temperatures sugar content show pyruvic acid, glucosidase and sugar content show irregular pattern. Bombay red onion bulb was stored for six months without significant change of quality attributes of onion bulb at storage temperature of 5 °C.
ARTICLE | doi:10.20944/preprints201803.0061.v1
Subject: Chemistry, Food Chemistry Keywords: Cucurbitaceae; gourd family; nutraceutical; antioxidant
Online: 8 March 2018 (03:48:02 CET)
Fruits of chayote [Sechium edule (Jacq.) Swartz] are widely consumed in Mesoamerica, but little is known about the nutraceutical potential. This study aimed to determine the chemical compositions, antioxidant activities from the juice fruits from two commercial varieties of chayote cultivated in Mexico, as well as a proposal for the elaboration of chayote juices with stevia leaves and pineapple juice. The physicochemical properties of juice from virens levis (VL) and nigrum spinosum (NS) varieties were determined using standard methods. The juice of the two varieties differ significantly regarding the concentrations of total soluble solids, total sugars, but not vitamin C. The total concentration of phenolics in NS extracts was slightly higher than in VL (1005 and 856 mg 100 g−1 dry-weight, respectively) but the total flavonoid contents were similar (27 and 26 mg 100 g−1 dry-weight, respectively). Cucurbitacin D was predominant in both varieties. The radical scavenging capacities of VL and NS extracts varied slightly (IC50 = 0.45 to 0.65 mg mL−1), while the antioxidant activities were similar (~80%). The NS variety is particularly promising regarding nutraceutical application. The chayote juice combined with stevia and pineapple maintain the original nutraceutical characteristics from the fruit, but enhanced the organoleptic characteristics like density and sugar/acidity balance.
ARTICLE | doi:10.20944/preprints201803.0053.v1
Subject: Chemistry, Food Chemistry Keywords: biogenic amines; chemometric analysis; DLLME, GC-MS; storage conditions; stopper type
Online: 7 March 2018 (13:08:12 CET)
1) Background: A survey of biogenic amines profile in opened wine bottles has been established. Opened bottles of red and white wine were submitted to different temperature as well as different kind of stopper (screw cap, cork stopper) and use of vacuum devices. A total of six wine made from different variety of grapes were obtained from Polish vineyard places in different region of Poland; 2) Results: DLLME-GC-MS procedure for biogenic amines determination was validated and applied for wine samples analysis. The total content of BAs in white wines ranged from 442 µg/L to 929 µg/L, while in red wines ranged from 669 µg/L to 2244 µg/L the set of just opened wine samples. The most abundant biogenic amines in the six analysed wines were histamine and putrescine; 3) Conclusion: Considering the commercial availability of the analysed wines, there was no relationship between the presence of biogenic amines in a given wine and their availability on the market. However, it was observed that the different storage conditions employed in this experiment affect not only the biogenic amines profile, but also the pH. The results were confirmed by chemometric analysis.
ARTICLE | doi:10.20944/preprints201801.0188.v1
Subject: Chemistry, Food Chemistry Keywords: caraway; cumin; bread quality; by-products; radical scavenging activity; total phenolic
Online: 26 January 2018 (03:59:04 CET)
This study investigated the effect of protein bread fortification with 2, 4 and 6% of cumin (Cuminum cyminum) and caraway (Carum carvi) whole seeds and by-products flour, respectively. Fortified protein bread samples were compared to control protein bread and evaluated for their sensory, color, moisture, hardness properties as well as their nutritional values. Total phenolic contents and Trolox equivalent antioxidant capacity were also analyzed. Results indicated that bread fortification shows significant effects on bread properties depending on fortification level. A higher acceptability was observed specially for bread fortified with by-products flour. Increased tendencies of color darkness, moisture content, bread hardness, nutritional values as well as total phenolic content and radical scavenging activity compared to control bread were observed as the percentage of fortification increased in both cases. The overall results showed that addition of cumin and caraway seeds and by-products flour can improve the antioxidant potential and overall quality of protein bread.
ARTICLE | doi:10.20944/preprints201711.0184.v2
Subject: Chemistry, Food Chemistry Keywords: Cistus incanus; Strandja; antioxidants; polyphenols; flavonoids; seasonality; buds; hard-coated seeds
Online: 2 January 2018 (11:21:12 CET)
The purpose of the present study is survey of extraction conditions and exploring antioxidant potential of the non-traditional for the Bulgarian ethno-medicine wild herb Cistus incanus widespread in Strandja Mountain. The influence of the extraction time (0–500 min) and solvent composition (0–50% ethanol in water) on the polyphenols, flavonoids yields and on antioxidant capacity of the extracts of leaves, stalks (wood parts) and buds mixture were studied. The antioxidant capacity (AOC) was evaluated by use of scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Total polyphenol and flavonoid contents were quantified using UV–vis spectrometry. Optimal yield of desired components has been obtained with 30% ethanol in water solvent at 390th min extraction time. In addition, the influence of the seasonality (winter and summer Cistus incanus), and of the different areal parts - hard-coated seeds; buds, and mixture of leaves and stalks of the wild plant on the presence of polyphenols, flavonoids and AOC were investigated. Present work revealed the high values of the polyphenols, flavonoids, the high AOC not only in the summer leaves, but also found in the winter leaves, hard-coated seeds, buds and stalks. Based on the obtained results the Cistus incanus from Strandja mountain could be a new excellent source of natural antioxidants in food and pharmaceutical industries.
ARTICLE | doi:10.20944/preprints201712.0018.v1
Subject: Chemistry, Food Chemistry Keywords: non-acylated anthocyanins; anthocyanins with aromatic acylation; SAR; mahaleb cherry; blackcurrant; black carrot; ‘Sun Black’ tomato; VCAM-1; ICAM-1; endothelial adhesion molecules
Online: 4 December 2017 (07:04:17 CET)
Anthocyanins, the naturally occurring pigments responsible for most red to blue colours of flowers, fruits and vegetables, have also attracted interests because of their potential health effects. With the aim of contributing to major insights into their structure-activity relationship (SAR), we have evaluated the radical scavenging and biological activities of selected purified anthocyanin samples (PASs) from various anthocyanin-rich plant materials: two fruits (mahaleb cherry and blackcurrant) and two vegetables (black carrot and ‘Sun Black’ tomato). PASs from the above-mentioned plant material have been evaluated for their antioxidant capacity, using TEAC and ORAC assays. In human endothelial cells, we analysed the biological activity of different PASs by measuring their effects on the expression of endothelial inflammatory markers, including endothelial adhesion molecules VCAM-1 and ICAM-1. We demonstrated that all the different PASs showed biological activity. They exhibited antioxidant capacity of different magnitude, higher for samples containing non-acylated anthocyanins (typical for fruits) compared to samples containing more complex anthocyanins acylated with cinnamic acid derivatives (typical for vegetables), even though this order was slightly reversed when ORAC assay values were expressed on molar basis. Concordantly, PASs containing non-acylated anthocyanins reduced the expression of endothelial inflammatory antigens more than samples with aromatic acylated anthocyanins, suggesting the potential beneficial effect of structurally diverse anthocyanins in cardiovascular protection.
ARTICLE | doi:10.20944/preprints201711.0065.v1
Subject: Chemistry, Food Chemistry Keywords: betanin; natural red; pigment; betalain; Opuntia; beet root
Online: 10 November 2017 (04:56:22 CET)
Sourced so far mostly from beet root juice, betanin is a red-violet natural colorant increasingly used by the food, beverage and nutraceutical industries. We provide an updated bioeconomy perspective into a valued betacyanin whose supply and applications, we argue in this study, will rapidly expand.
ARTICLE | doi:10.20944/preprints201710.0145.v1
Subject: Chemistry, Food Chemistry Keywords: Opuntia ficus-indica; nutraceutical; betanin; pectin; natural colorant
Online: 23 October 2017 (03:57:04 CEST)
The integral extraction via microwave-assisted hydrodiffusion and hydrodistillation of water-soluble bioproducts contained in the peel of Opuntia ficus-indica white and red cultivars harvested in Sicily, affords red and stable aqueous extracts mostly containing valued betanin, pectin and biophenols. Potentially useful as nutraceutical products, these aqueous extracts are a source of valued ingredients in high demand for a number of important food, cosmetic, beverage and nutraceutical applications.
ARTICLE | doi:10.20944/preprints201709.0052.v1
Subject: Chemistry, Food Chemistry Keywords: Vitamin E; GC-FID; Uncertainty; Cereal products; Reference daily value; Health claim
Online: 13 September 2017 (14:13:00 CEST)
A rapid, precise, accurate and low cost method for the determination of vitamin E (α-tocopherol) in cereal products and biscuits was developed. The uncertainty was calculated for the first time and the methods were performed in different cereal products and biscuits, characterized as “superfoods”. The limits of detection and quantification were calculated. Accuracy and precision were estimated using the certified reference material FAPAS T10112QC and the determined values were in good accordance with the certified values. The health claims according to the daily reference values for vitamin E were calculated and the results proved that the majority of the samples examined showed %daily value higher than 15%.
ARTICLE | doi:10.20944/preprints201709.0039.v1
Subject: Chemistry, Food Chemistry Keywords: stable carbon isotope analysis; lipids; fatty acids; Cordyceps sinensis; the Qinghai-Tibetan Plateau
Online: 11 September 2017 (08:06:30 CEST)
Cordyceps sinensis is one rare medicinal fungus produced in the Qinghai-Tibetan Plateau. Its quality and price varies hugely with different habitat, and its numerous substitutes have sprung up in functional food markets. This paper aims to discriminate the geographic origin of wild C. sinensis and its substitutes via the element analyzer-isotope ratio mass spectrometry and gas chromatography-isotope ratio mass spectrometry. The δ13C values of major fatty acids in the lipids of Cordyceps sinensis are characterized unanimously by the variation relation C18:0 ﹤ C18:2 ≈ C16:0 ﹤ C18:1; while their fluctuation intervals are notably different between those of neutral and polar lipids. The comparative analysis of the δ13C ratios of major fatty acids in lipids of Cordyceps sinensis suggests that the δ13C patterns may be sensitive potential indicators to discriminate its geographical origin. The δ13C values of individual major fatty acids of lipids from the cultivated stromata of Cordyceps militaris (SCM), the fermented mycelia of Hirsurella sinensis (FMH) and Paecilomyces epiali (FMP) range from −31.2‰ to −29.7‰, −16.9‰ to −14.3‰, and −26.5‰ to −23.9‰, respectively. Their δ13C pattern of individual major fatty acids may be used as a potential indicator to discriminate the products of natural C. sinensis and its substitutes.
ARTICLE | doi:10.20944/preprints201709.0017.v1
Online: 5 September 2017 (17:36:25 CEST)
Cheap licit and artisanal illicit spirit drinks have been associated with numerous outbreaks of alcohol poisoning especially with methanol. This study aimed to evaluate the quality of cheap spirit drinks in Kibera slums in Nairobi County, Kenya. The samples consisted of cheap licit spirits (n=11) and the artisanal spirit drink, ‘chang’aa’, (n=28). The parameters of alcoholic strength and volatile composition were used as indicators of quality and were determined using GC-FID and GC-MS respectively. The pH of chang’aa was 3.3-4.2 and 4.4-8.8 for licit spirit drinks while ranges for alcoholic strength were 42.8-85.8 % vol. and 28.3-56.7% vol. for chang’aa and licit spirit drinks respectively. The majority of volatiles were found in artisanal spirits and they included higher alcohols, ethyl esters and carbonyl compounds. The alcoholic strength of all the artisanal spirits (100%) and 91% of the licit spirits was above the 40% vol. of standard spirits such as vodka. The high ethanol content of the alcohol products was the only element of public health significance in this study.
ARTICLE | doi:10.20944/preprints201705.0219.v1
Subject: Chemistry, Food Chemistry Keywords: Akebia quinata extracts; alcohol; liver disease; CYP2E1; COX-2
Online: 31 May 2017 (11:38:36 CEST)
In this study, we investigated the effects of Akebia quinata ethanol extract (AE), Akebia quinata sikhye (AS), and Akebia quinata water extract (AW) on alcohol-induced liver injury in rats. The hepatoprotective, anti-inflammatory, anti-apoptotic, and antioxidant effects of AE, AS, and AW were examined. Experimental animals were randomly divided into five groups: normal, ethanol, AE (10 mL/kg), AS (10 mL/kg), and AW (10 mL/kg). Each group was administered the respective treatment orally once per day for 21 days. CYP2E1 mRNA expression was significantly lower in the AE, AS, and AW groups than that in the ethanol group. Pro-inflammatory cytokines including cyclooxygenase-2, IL-6, and TNF-α increased significantly in the ethanol group but these increases were ameliorated with AE, AS, and AW treatment. Moreover, the expression of the apoptosis-associated proteins Bax, p53, procaspase-3, and PARP decreased after treatment with AE, AS, and AW. The expression of antioxidant enzymes including BCL-2, SOD, and GST slightly decreased in the ethanol group, but AE, AS, and AW treatment augmented their activities. AQ extracts and AS attenuated ethanol-induced increases in the levels of phosphorylated p-AKT, p-ERK, and p-JNK. These results demonstrate that AQ is a competence indicator for inhibiting alcoholic liver injury.
ARTICLE | doi:10.20944/preprints201705.0218.v1
Subject: Chemistry, Food Chemistry Keywords: anticancer activity; apoptosis; oleanolic acid; cell cycle arrest; mapk signaling
Online: 31 May 2017 (11:28:30 CEST)
We evaluated oleanolic acid (OA)-induced anti-cancer activity, apoptotic mechanism, cell cycle status, and MAPK kinase signaling in DU145 (prostate cancer), MCF-7 (breast cancer), and U87 (human glioblastoma) cells. The IC50 values for OA-induced cytotoxicity were 112.57 in DU145, 132.29 in MCF-7, and 163.60 in U87 cells, respectively. OA (at 100 µg/mL) increased the number of apoptotic cells to 27.0% in DU145, 27.0% in MCF-7, and 15.7% in U87 cells, when compared to control cells. This enhanced apoptosis was due to increases in p53, cytochrome c, and Bax expression. OA-treated DU145 cells were arrested in G2 because of the activation of p-ERK and p21, and the decrease in cyclin B1 and cyclin E expression. Furthermore, OA-treated MCF-7 cells were arrested in G1 owing to the activation of p-JNK, p-ERK, p21, and p27, and the decrease in p-AKT, cyclin E, and CDK2. U87 cells also exhibited G1 phase arrest caused by the increase in p-ERK, p-JNK, p21, and p27, and the decrease in CDK2. Thus, OA arrests the cell cycle in different phases, and increases apoptosis in cancer cells. These results suggest that OA may alter the expression of cell cycle regulatory proteins in a cancer type-dependent manner.
REVIEW | doi:10.20944/preprints201705.0200.v1
Subject: Chemistry, Food Chemistry Keywords: Diet: Functional foods: Western foods: Mediterranean foods: Feeding, Plant breeding
Online: 29 May 2017 (17:38:59 CEST)
There is evidence that optimal nutrition is fundamental to human health and in the prevention of non-communicable diseases (NCDs) later in adult life. The identification, production and consumption of functional foods worldwide can increase health benefits for all who can access and afford such foods subject to advice from nutritionists. Recent meetings organized by the health agencies, give a crucial opportunity to make nutrition, a central part of the post-2015 sustainable human and agricultural development agenda. The aim of discussions in these meetings was to provide functional crops and foods to achieve optimal health by prevention of NCDs. It is possible that these efforts might ensure that the goals and targets set in the agenda are adequate to address the many challenges of global undernutrition as well as obesity which are major risk factors of NCDs. In many developing and middle income countries, food security provided by the governments, in one sense understandably, gave least consideration to functional foods supply and the prevention of obesity and metabolic syndrome, resulting in to emergence of NCDs. The Thailand Declaration reiterates that commitments to eradicate hunger and undernutrition as well as over-nutrition, and to increase investments in effective interventions; designers foods and designers crops. However, in planning coherent policies, our past experience on rapidly absorbed, energy-rich processed foods should be taken in to account while developing sustainable food systems. The food industry should be educated to exploit the expertise of food scientists and health professionals in designing functional foods taking cognizance of manufacturing and processing. Similarly, agriculture scientists may be actively involved in educating farmers so as to grow cash crops providing functional foods. The aim should be to achieve an increase in the availability of functional foods to an extent, or by a policy, by which such foods are available to poors, at affordable cost to prevent hunger and undernutrition and related diseases as well as NCDs. In addition our efforts might help in developing an international consensus on how to approach the development of new designer foods by farmers and food industry to produce low glycemic index foods. Such efforts may establish an international framework for the prevention of NCDs, so that human susceptibility to these diseases is substantially diminished.
ARTICLE | doi:10.20944/preprints201705.0078.v1
Subject: Chemistry, Food Chemistry Keywords: Euterpe oleracea; Astrocaryum acaule; Mauritia aculeata; Mauritia flexuosa; PUFA; MUFA
Online: 9 May 2017 (05:05:45 CEST)
Native plants from the Brazilian Amazon Biome are rich in nutrientes, oils and fats and, therefore, represent a very important regional food resource. Althoung there is a global interest in the nutritional potential of tropical fruits, the potential of Amazonian fruits as source of essential fatty acids is still under exploited, since their composition is still understudied. 1H Magnetic Resonance Nuclear (1H NMR) is a robust spectroscopic tool to profile fatty acids components in oils. The objectives of this work were to use 1H NMR to determine the fatty acids profile and the physicochemical properties of crude oils and fats obtained from fruits of Brazilian Amazon: açaí, ata-brava, bacaba, buriti, buritirana, murici amarelo, murici vermelho, piaçaba braba, tucumanzinho, pupunha red and yellow varieties. Oils were obtained by Soxhlet extraction using hexane as a solvent. After solvent removal by rotoevaporation, the resulting oils and fats were analyzed by 1H NMR spectroscopy. Unsaturated fatty acids oleic (ω9), linoleic (ω6) and linolenic (ω3) acids were quantified in the oils and their physicochemical properties were determined. It was observed that the oils have predominately ω9 fatty acids, followed by ω6 and ω3 representatives. The physicochemical properties confirmed edibility and good quality of oils and fats present in the aforementioned Amazonian fruits.
ARTICLE | doi:10.20944/preprints201703.0194.v1
Subject: Chemistry, Food Chemistry Keywords: aromatic plants; HPLC; antioxidant capacity; DPPH; Rancimat test
Online: 27 March 2017 (09:57:43 CEST)
The antioxidant properties and polyphenol content of some selected aromatic plants grown in Greece were studied. Plants were refluxed with 60% methanol after acid hydrolysis. The phenolic substances were quantified by HPLC-DAD. The antioxidant capacity of the extracts was determined with the Rancimat test using sunflower oil as substrate. Free radical scavenging activity was measured using the stable free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Results were compared with standard BHT and ascorbic acid. Total phenol concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard.
ARTICLE | doi:10.20944/preprints201703.0181.v1
Subject: Chemistry, Food Chemistry Keywords: total aflatoxin; quantum dot nanobead; test strip; on-site; peanut and rice; agro-food safety
Online: 24 March 2017 (03:59:06 CET)
An on-site, ultra-sensitive, and quantitative sensing method was developed based on quantum dot nanobeads (QDNBs) and test strip for the determination of total aflatoxins (AFTs) in rice and peanut. The monoclonal antibody against AFT (mAbAFT) was home-made and labeled with QDNB. After the pre-coating of the AFT antigen on the test line (T line), the competitive immunoreactions were conducted between AFT and AFT antigen on the T line with QDNBs-mAbAFT. Under optimal conditions, this approach allowed a rapid response towards AFT with a considerable sensitivity of 1.4 pg/mL and 2.9 pg/mL in rice and peanut matrices, respectively. The put-in and put-out duration were within 10 min. The recoveries for AFT in rice and peanut samples matrices were recorded from 86.25–118.0% with the relative deviations (RSD) below 12%. The assay was further validated via the comparison between this QDNB strip and the conventional HPLC method using spiked samples. Thus, the design provided a potential alternative for on-site, ultra-sensitive, and quantitative sensing of AFT that could also be expanded to other chemical contaminants for food safety.
ARTICLE | doi:10.20944/preprints201701.0084.v1
Subject: Chemistry, Food Chemistry Keywords: onions; A. × cornutum; A. cepa; phenolic compounds; antioxidant activity; genotoxicity; antimutagenic activity; antiproliferative activity
Online: 19 January 2017 (02:09:32 CET)
Here we report a comparative study of the pyhtochemical profile and a biological activity of the two onion extracts, namely A. cepa L. and A. × cornutum (Clementi ex Visiani 1842). Identification of flavonoids and anthocyanins and their individual quantities were determined by high performance liquid chromatography (HPLC). The potency of both extracts to scavenge free radicals was determined by DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical-scavenging activity and oxygen radical absorbance capacity (ORAC) methods. DNA protective role was further tested by single-cell gel electrophoresis (COMET) assay and by Fenton’s reagent causing double strand brakes on pUC19 plasmid. In the presence of both extracts, a significant decrease in the DNA damage was observed, which indicates a protective role of A. cepa and A. × cornutum on the DNA strand brakes. Additionally, cytotoxicity was tested on glioblastoma and breast cancer cell lines. The results showed that both extracts had antiproliferative effect, but the most prominent decrease in cellular growth was observed with glioblastoma cells