ARTICLE | doi:10.20944/preprints202209.0190.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: green coffee bean; lightweight framework; deep convolutional neural network; explainable model; random optimization
Online: 14 September 2022 (04:04:05 CEST)
In recent years, the demand for coffee has increased tremendously. During the production process, green coffee beans are traditionally screened manually for defective beans before they are packed into coffee bean packages; however, this method is not only time-consuming but also increases the rate of human error due to fatigue. Therefore, this paper proposed a lightweight deep convolutional neural network (LDCNN) for the quality detection system of green coffee beans, which combined depthwise separable convolution (DSC), squeeze-and-excite block (SE block), skip block, and other frameworks. To avoid the influence of low parameters of the lightweight model caused by the model training process, rectified Adam (RA), lookahead (LA), and gradient centralization (GC) were included to improve efficiency; the model was also put into the embedded system. Finally, the local interpretable model-agnostic explanations (LIME) model was employed to explain the predictions of the model. The experimental results indicated that the accuracy rate of the model could reach up to 98.38% and the F1 score could be as high as 98.24% when detecting the quality of green coffee beans. Hence, it can obtain higher accuracy, lower computing time, and lower parameters. Moreover, the interpretable model verified that the lightweight model in this work is reliable, providing the basis for screening personnel to understand the judgment through its interpretability, thereby improving the classification and prediction of the model.
REVIEW | doi:10.20944/preprints202108.0123.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: metabolic syndrome; caffeinated coffee; decaffeinated coffee; green coffee extract; chlorogenic acid
Online: 4 August 2021 (22:04:19 CEST)
Coffee is rich in phenolic acids, such as caffeic acid and chlorogenic acid (CGA). Polyphenol-rich diets have been shown to reduce the risk of metabolic syndrome (MeTS). Background and Objectives: This systematic review and meta-analysis discusses the effects of coffee consumption and its dose-response on MeTS parameters. Materials and Methods: PubMed and Scopus® were searched for relevant articles published between 2015 and 2020. This review focused on randomised controlled trials (RCTs) investigating the effect of coffee consumption on anthropometric measurements, glycaemic indices, lipid profiles, and blood pressure. Data from relevant studies were extracted and analysed using random, fixed, or pooled effects models with 95% confidence intervals (CIs). Results: Green coffee extract (GCE) supplementation (180 to 376 mg) was found to reduce waist circumference (weighted mean difference (WMD) = -0.39; 95% CI: -0.68, -0.10), triglyceride levels (WMD = -0.27; 95% CI: -0.43, -0.10), high-density lipoprotein-cholesterol levels (WMD = 0.62; 95% CI: 0.34, 0.90), systolic blood pressure (WMD = -0.44; 95% CI: -0.57, -0.32), and diastolic blood pressure (WMD = -0.83; 95% CI: -1.40, -0.26). Decaffeinated coffee (510.6 mg) reduced the fasting blood glucose levels (WMD = -0.81; 95% CI: -1.65, 0.03). The meta-analysis showed that the intake of GCE containing 180 to 376 mg of CGA (administered in a capsule) and liquid decaffeinated coffee containing 510.6 mg of CGA improved the MeTS outcomes in study participants. Conclusions: The findings of the review suggested that the effect of coffee on MeTS parameters varies depending on the types and doses of coffee administered. A more detailed RCT on specific coffee doses (with adjustment for energy and polyphenol intake) and physical activity is needed to further confirm the observed outcomes.
ARTICLE | doi:10.20944/preprints201809.0111.v1
Subject: Social Sciences, Marketing Keywords: consumer preferences; coffee market; coffee; research results
Online: 6 September 2018 (05:59:23 CEST)
The article addresses the issue of consumer preferences for types of coffee in Poland (ground coffee, instant coffee, coffee beans, instant coffee mixes and instant cappuccino). The main source of the study is the results of primary research conducted using a structured interview (CAPI—Computer Assisted Personal Interview) on a nationwide sample of 800 coffee consumers. The research was conducted by Grupa IQS Sp. z o.o. from Warsaw in January 2016 for the MOKATE Group based on the assumptions and guidelines developed by the authors of the article. The main purpose of the article is to present the identified coffee consumer preferences in Poland with regard to various kinds of coffee. The results of the research which have been included in the article indicate, among others, ongoing changes in the preferences of Polish consumers regarding their coffee choices. They prove that Polish consumers are drinking ground coffee more and more often. The consumption of instant coffee is decreasing.
ARTICLE | doi:10.20944/preprints202011.0706.v1
Subject: Life Sciences, Biochemistry Keywords: Chlorogenic acid; coffee; cyclooxygenase; espresso; instant coffee; platelet aggregation
Online: 30 November 2020 (08:07:40 CET)
Coffee is rich in caffeine (CF), chlorogenic acid (CGA) and phenolics. Differing types of coffee beverages and brewing procedures may result in differences in total phenolic contents (TPC) and biological activities. Inflammation and increases of platelet activation and aggregation can lead to thrombosis. We focused on determining the chemical composition, antioxidant activity and inhibitory effects on agonist-induced platelet aggregation and cyclooxygenase (COX) of coffee beverages in relation to their preparation method. We prepared instant coffee and brewed coffee beverages using drip, espresso and boiling techniques. Coffee extracts were assayed for their CF and CGA contents using HPLC, TPC using colourimetry, platelet aggregation with an aggregometer and COX activity using ELISA. The findings have shown all coffee extracts, except the decaffeinated types, contained nearly equal amounts of CF, CGA and TPC. Inhibitory effects of coffee extracts on platelet aggregation differed depending on the activation pathways induced by different agonists. All espresso, drip and boiled coffee extracts caused dose dependent inhibition of platelet aggregation induced by ADP, collagen, epinephrine, and arachidonic acid (ARA). The most marked inhibition was seen at low doses of collagen or ARA. Espresso and drip extracts inhibited collagen-induced platelet aggregation more than purified caffeine or CGA. Espresso, boiled and drip coffee extracts were also a more potent inhibitors of COX-1 and COX-2 than purified caffeine or CGA. We conclude that inhibition of platelet aggregation and COX-1 and COX-2 may contribute to anti-platelet and anti-inflammatory effects of espresso and drip coffee extracts.
ARTICLE | doi:10.20944/preprints202209.0028.v1
Online: 2 September 2022 (02:41:17 CEST)
Introduction: Blood pressure is described as the ratio of systolic pressure to diastolic pressure, with its normal values ranging from 100/60 to 140/90. For the risk of blood pressure, both men and women have the possibility of developing hypertension. The habits of people who consume coffee will impact increasing blood pressure. The frequency of drinking coffee over 3 cups per day can affect blood pressure, although fact, only because of this habit that a person has an increase in blood pressure. Aims: This study aims to determine the relationship between coffee drinking habits and increased blood pressure in the community. Method: This type of research uses an analytical description research method with a cross-sectional design of e population of the community around Pontianak city the habit of drinking coffee. The samples in this study were 50 people with a sampling technique using Probability sampling, namely with the Stratified Random Sampling technique. Data collection for coffee drinking habits using questionnaire sheets and observation sheets using a sphygmomanometer. Data analysis used Person Chi-Square and obtained p-value = 0.312 (p>0.05%). Result: These results showed that there was between coffee drinking habits and an increase in blood pressure. Conclusion: Researchers advise health workers to provide health promotion about coffee drinking rules and coffee drinking doses that are good for health.
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/preprints201805.0382.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: dependence; nicotine; tobacco; coffee
Online: 28 May 2018 (05:16:08 CEST)
Introduction. Few studies have compared the dependence to different tobacco and nicotine products. Besides how dependence may vary between tobacco products there is even less known how it relates to other common drugs, e.g. caffeine. In this study degree of dependence was compared between snus, cigarettes, nicotine replacement (NR), electronic cigarettes and coffee. Methods. An internet panel was used to obtain a representative sample of 3001 Swedes. The responders were asked among other related things about their use of snus, NR, traditional cigarette or e-cigarette use and coffee consumption. The indicators of dependence used were: A. the Heavy Smoking Index, B. The proportions that used within 30 min after raising in the morning, C. rating the first use in the morning as the most important and D. Stating that it would be very hard to give up entirely. Results. Significantly fewer among coffee drinkers started use within 30 minutes of awakening compared with all other products. The first use of the day was found to be more important for snus users compared with other products. On HSI there was no difference between snus and cigarettes. Snus and cigarettes were rated as being more difficult to give up than NR and coffee. Conclusion. Dependence to traditional cigarettes and snus seem to be relatively similar while NR was rated lower and coffee lowest. Since the prevalence of caffeine use in all forms is so much more prevalent than nicotine use there might be more persons in the society heavily dependent on caffeine. Implication. Tobacco products are likely more dependence forming that NR products and coffee. The addiction to coffee or caffeine is seldom discussed in the society. But if there are more individuals heavily dependent on coffee than nicotine and some nicotine containing products like snus and even more so NR are not that much more harmful than coffee how problematic is the addiction?
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/preprints201807.0313.v1
Subject: Chemistry, Analytical Chemistry Keywords: elephant dung coffee; volatile compound; discriminant marker; SHS GC–MS; chemometrics; coffee authentication
Online: 17 July 2018 (15:02:03 CEST)
Elephant dung coffee (Black Ivory Coffee) is a special Thai coffee produced from Arabica coffee cherries consumed by Asian elephants and collected from their feces. In this work, elephant dung coffee and controls were analyzed using static headspace gas chromatography hyphenated with mass spectrometry (SHS GC–MS), and chemometric approaches were applied for multivariate analysis and the selection of marker compounds that are characteristic of the coffee. Seventy-eight volatile compounds belonging to 13 chemical classes were tentatively identified, including 6 alcohols, 5 aldehydes, one carboxylic acid, 3 esters, 17 furans, one furanone, 13 ketones, 2 oxazoles, 4 phenolic compounds, 14 pyrazines, one pyridine, 8 pyrroles and 3 sulfur-containing compounds. Moreover, four potential discriminant markers of elephant dung coffee, including 3-methyl-1-butanol, 2-methyl-1-butanol, 2-furfurylfuran and 3-penten-2-one were established. The proposed method may be useful for elephant dung coffee authentication and quality control.
ARTICLE | doi:10.20944/preprints202104.0053.v1
Online: 2 April 2021 (11:32:05 CEST)
As an export commodity coffee industry contributes to the economies of both exporting and importing countries. The aim of the study involves competitiveness and determinant of coffee export in Ethiopia through the period of 1990–2018 observations. To explain the level of comparative advantage and competitiveness respectively Revealed Comparative Advantage and Syematric Revealed Comparative Advantage were employed. To capture determinans of coffee ARDL model with bound testing to co-integration approach was employed to investigate the long-run association between Ethiopian total coffee export in bags (60kg each) with domestic coffee production, world coffee price, real exchange rate, FDI, world coffee production and price ratio. Even though Ethiopia has the comparative advantage in the export of coffee, however, the share it in the international market low in amount and not inlined with RCA. Bound testing to co-integration approach result confirmed the existence of a long-run relationship between total coffee exports of Ethiopia with its independent variables. The analysis pointed out that in the long run the extent of domestic coffee production, world price, and real exchange rate positively and significantly affects total coffee export. However, FDI, price ratio, world production of coffee have negative & significant effects. In the short-run Ethiopian total coffee export defined as a positive significant function of domestic coffee production and real exchange rate positive but insignificant effect with Level of RCA and world price as well as a negative function of FDI, price ratio, and world production of coffee. Coefﬁcient Error Correction Model (ECM (-1)) was negative and signiﬁcant with a value of 134.4 % of the adjustment would make each year and return to its long-run equilibrium after 1.3 years. The policy implication calls for addressing issues of the combined effect of the policy setting, institutions, and market failures to avoid the evil effect of the sector.
BRIEF REPORT | doi:10.20944/preprints202005.0280.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: coffee; stomach neoplasms; incidence; mortality
Online: 17 May 2020 (03:18:01 CEST)
Background: Coffee is the second most popular drink in the worldwide, and it has different components with antioxidant and antitumor properties. The objective of this study was to explore the relationship between coffee consumption and the incidence and mortality of stomach cancer in the main consuming countries. Methods: An observational study was performed. Dataset of coffee consumption was obtained from WorldAtlas, and incidence and mortality rates from GLOBOCAN database. Spearman's rank correlation coefficient was calculated. All statistical analysis were performed using STATA software. Results: A total of 25 countries were included in the study. There was a significant linear correlation between coffee consumption kg per person per year and an estimated age-adjusted incidence (r=0.5984, p=0.0016) and mortality (r=0.5877, p=0.0020). Conclusion: Coffee consumption could potentially have beneficial effects on incidence and mortality by stomach cancer.
REVIEW | doi:10.20944/preprints202106.0085.v2
Online: 3 June 2021 (13:36:26 CEST)
Kenyan coffee is ranked among the best in the world and 99% is exported mainly to Germany, Sweden and Belgium, the USA and Saudi Arabia. Kenya produces quality Arabica beans which are generally recognized and upgraded with other relatively lower brands. In 1937, the Kenya Planters Cooperative Union (KPCU) was formed to represent small farmers' interests. In 1944, in the Coffee Board of Kenya (CBA) the law required smallholders to join local growing cooperatives run by government to reduce the power of large estates to control the board. Many reforms in the coffee industry have been initiated. This review explores evolution and existing coffee varieties in Kenya, the coffee value chain and the regions that grow coffee in Kenya. Additionally, the variety agronomics and appearance that encompass; quality potential at different altitudes, yield potential and nematodes susceptibility.
ARTICLE | doi:10.20944/preprints202010.0445.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Obesity; Garcinia cambogia; Green Coffee; Pakistan
Online: 21 October 2020 (16:52:38 CEST)
Introduction: Various studies have widely documented how weight (being overweight, underweight or obese) plays a significant role in increasing health problems and adversely affects the quality of life. Out of all the weight-related issues, obesity is the number one contributing factor for causing health problems. To overcome this factor, a trial was conducted where a drug 'Lite plus’ (Garcinia Cambogia and Green Coffee bean) was given to a select number of people for a period of three months. Materials and Methods: 'Lite Plus' is a drug which contains Garcinia cambogia 500 mg + Green Coffee Bean Extract 400 mg, with a recommended dosage of 2 tablets/day with or before meals for 3 months. Most of the patients included in our study were females suffering from obesity-related problems such as PCOs and Infertility. During the trial, all patients were given the recommended dosage of 'Lite plus', while those with diabetes had the dose amended accordingly. Results: As a result of this trial, it was found that the use of 'Lite Plus' was very effective in decreasing weight/BMI with continuous use. After 6 weeks, out of the 250 respondents participating in the trial, 232 got a reduction in their BMI, and after 12 weeks (end of the trial), 29 respondents (11.6%) reached the desired level of BMI. Conclusion: Garcinia cambogia and Green Coffee bean are effective and safe in weight reduction.
REVIEW | doi:10.20944/preprints201808.0405.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: caffeine; coffee; systematic review; pregnancy; safety
Online: 23 August 2018 (05:33:43 CEST)
In 2016–2017, we conducted and published a systematic review on caffeine safety  that set out to determine whether conclusions presented in the heavily cited Health Canada assessment, Nawrot et al. , remain supported by more recent data. To that end, we reviewed data from 380 studies published between June 2001 and June 2015, which were identified from an initial batch of over 5,000 articles through a stringent search and evaluation process . In the current paper, we use plain language to summarize our process and findings, with the intent of sharing additional context for broader reach to the general public. We addressed whether caffeine doses previously determined not to be associated with adverse effects by Health Canada (400 mg/day for healthy adults, 300 mg/day for pregnant women, 2. 5 mg/kg body weight/day for adolescents and children, and 10 g/day for acute effects) remain appropriate for five outcome areas (acute toxicity, cardiovascular toxicity, bone & calcium effects, behavior, and development and reproduction) in healthy adults, pregnant women, adolescents, and children. We used a weight-of-evidence approach to draw conclusions for each of the five outcomes, as well as more specific endpoints within those outcomes, which considered study quality, consistency, level of adversity, and magnitude of response. In general, updated evidence confirms the levels of intake put forth by Nawrot et al., as not being associated with any adverse health effects, and our results support a shift in caffeine research from healthy to sensitive populations.
ARTICLE | doi:10.20944/preprints202106.0602.v1
Subject: Engineering, Automotive Engineering Keywords: classifier; coffee beans; efficiency; specific energy; sieves
Online: 24 June 2021 (11:22:48 CEST)
Nowadays, some coffee production centers are still classification manually, so it requires a very long time, a lot of labor, and expensive operational costs. Therefore, the purpose of this research was to design and performance of the coffee bean classifier that can accelerate the process of classification beans. The classifier used consists of three main parts, namely the frame, driving force, and sieves. Research parameters include classifier work capacity, power, specific energy, classification distribution and effectiveness, and efficiency. The results showed that the best operating conditions of the coffee bean classifier was found at a rotational speed of 91.07 rpm and a 16° sieves angle with a classifier working capacity of 38.27 kg/h, the distribution of the seeds retained in the first sieve was 56.77 %, the second sieves was 28.12%, and the third sieves was 15.11%. The efficiency of using a classifier was found at a rotating speed of 91.07 rpm and a sieves angle of 16°. This classifier was simple in design, easy to operate, and can sort coffee beans into three classification, namely small, medium, and large.
ARTICLE | doi:10.20944/preprints202104.0322.v1
Subject: Biology, Anatomy & Morphology Keywords: Coffee arabica; Hypothenemus hampe; baited traps; IPM
Online: 12 April 2021 (21:06:14 CEST)
The coffee industry loses millions of dollars annually worldwide due to the Coffee Berry Borer (CBB); these losses imply a decrease in quality and production. Traps are used to monitor their flight and for pest control. The main objective was to determine the flight pattern and trap capture percentages of the CBB population over time using column traps (CTs) in two independent field experiments. CTs were composed of four traps installed at four different heights 0.5, 1.5, 2.5, and 3.5m above ground. Our results demonstrated a significant difference in CBB capture by traps placed at different heights above the ground. The CT capture maintained a pattern throughout this study's lag; the lower the height, the greater the percentage of CBBs captured. In Experiments A and B, the traps placed at 0.5m caught 67% and 85% of the CBBs captured, respectively. Furthermore, the trap set at 1.5m above the ground in the multi-level CT showed a higher capture percentage than the individually placed trap (also at 1.5m). The pattern of the capture and proportion of the CBB in the CTs were maintained throughout the study despite the season, changes in temperature, and relative air humidity. We suggested that CTs could be explored as a useful tool for capturing the CBB, considering its monitoring and management.
ARTICLE | doi:10.20944/preprints202103.0083.v1
Subject: Engineering, Automotive Engineering Keywords: thermogravimetry; wastes; pyrolysis; polyethylene; polystyrene; coffee husks
Online: 2 March 2021 (11:57:14 CET)
Research abounds in the literature on kinetic analyses using thermogravimetric (TG) runs. Many of these studies use approximations of integral or derivative forms of the kinetic law and all of them use programmed temperature, not the actual temperature measured by thermocouples close to the sample. In addition, it is common to conduct a single run in order to perform the calculation. Nevertheless, many authors consider that numerical methods should be used to analyse the kinetics of decomposition. In such cases, the actual temperature is used and, generally, several runs are fitted using the same kinetic parameters, giving robustness to the results. In the present work, a numerical integration procedure was discussed and applied to different examples. We focused on materials presenting a single decomposition curve as well as other materials with more complex processes. Different examples were explored, and the methodology was applied to a number of wastes such as coffee husks, polystyrene and polyethylene.
ARTICLE | doi:10.20944/preprints201909.0213.v1
Subject: Chemistry, Analytical Chemistry Keywords: chlorogenic acid; extraction; coffee silverskin; analytical method
Online: 18 September 2019 (17:21:05 CEST)
Chlorogenic acid or 5-Caffeoylquinic acid is a polyphenolic component present in coffee and its by-products. Chlorogenic acid has been shown to exert biological properties, particularly in relation to glucose and lipid metabolism, including antibacterial, antioxidant, anti-inflammatory activities, among others. Due to its importance, it is necessary to evaluate the reliability of the analytical method for its determination in complex matrices such as food. In this work, different methods of chlorogenic acid extraction in coffee Silverskin were studied, as well as its quantification by HPLC. The results showed that the method of extraction with a mixture of methanol:water (3:1 v/v) in an ultrasonic bath, favored the recovery of chlorogenic acid with a recovery of 77.44%. The instrument detection limit for chlorogenic acid was 3.311 µg/mL and the quantification limit was 11.037 µg/mL. For coffee Silverskin, the concentration obtained of chlorogenic acid by the three extraction methods evaluated was in the range of 57 to 224 mg/kg of coffee silverskin (dry basis).
ARTICLE | doi:10.20944/preprints201908.0076.v1
Subject: Chemistry, Applied Chemistry Keywords: dysprosium; activated carbon; spent coffee ground; adsorption
Online: 6 August 2019 (12:23:23 CEST)
This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous and favorable process.
ARTICLE | doi:10.20944/preprints201808.0541.v1
Subject: Engineering, Other Keywords: anaerobic process; biogas; coffee wastewater; digester construction
Online: 31 August 2018 (05:47:42 CEST)
Wet coffee processing methods will produce wastewater containing organic matter. The high content of organic matter can be utilized as biogas through the anaerobic process. Anaerobic digesters construction can affect removal process of wastewater pollution and biogas quantity. The purpose of this study is to determine the effect of digester construction between conventional digester, CSTR and UASB producing biogas from coffee wastewater. The conventional digester worked without temperature control system as control, a UASB digester, and CSTR digester worked with temperature control system. Biomass volume was about 5 L with 35 days incubation time. Temperature and pH for UASB and CSTR were set within the range 30 – 35oC and pH 6.0 – 8.0. Based on the feeding variations, UASB has a stable performance with 83.57 ml/day of average biogas production. It has also highest remediation efficiency of COD, BOD and C/N with 85.00±0.34 %, 84.40%± 5.66 and 97.78± 0.57.
ARTICLE | doi:10.20944/preprints201709.0165.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: coffee; obesity; body mass index; waist circumference
Online: 30 September 2017 (05:12:52 CEST)
The objective of this study was to investigate the relationship between coffee consumption and obesity in Korean women. We included 5,995 women who participated in a health screening examination at the Korean National Cancer Center between 2007 and 2016. Daily coffee consumption was evaluated using the food frequency questionnaire. Obesity was assessed by body mass index (BMI), and abdominal obesity was assessed by waist circumference (WC). A multiple logistic regression model was used to calculate the odds ratio (OR) of obesity according to coffee consumption. After multivariate adjustment, high coffee consumption was positively associated with obesity measured by BMI (≥ 3 cups vs. no drinks, OR = 2.52; 95% confidence interval (CI) = 1.91-3.34; P for the trend < 0.001) and abdominal obesity measured by WC (≥ 3 cups vs. no drinks, OR = 2.11; 95% CI = 1.59-2.79; P for the trend < 0.001). The positive association between daily coffee consumption and obesity prevalence was not altered by menopause. The amount of coffee consumed per day by Korean women was positively correlated with the prevalence of obesity, but the mechanism underlying this phenomenon remains to be elucidated.
ARTICLE | doi:10.20944/preprints202005.0254.v1
Online: 15 May 2020 (10:22:59 CEST)
In addition to being a source of freshener, coffee has an enormous possibility to be developed as a source of antioxidants for functional beverages. However, efforts to increase the value added of coffee as a health functional drink are still hindered by the presence of high level of caffeine, which is thought to have adverse effects on health, especially for coffee lovers who are vulnerable to caffeine. This study aims to optimise the steaming duration to produce low caffeine coffee while maintaining the sensory attributes and antioxidant compounds contained in it. Indonesian Arabica (Leksana variety) green coffee beans were steamed with multi-level steaming durations (0, 20, 40, 60 and 80 min) followed by roasting (medium-dark roast degree), grinding, and brewing (espresso method). The results indicate that caffeine content in the coffee was inversely proportional to the steaming duration. The lowest caffeine content was obtained from the treatment of 80 min steaming with a decrease of caffeine level up to 28.73%. However, the longer process of steaming caused a significant decrease in polyphenol content and antioxidant activity. The hedonic test shows that the steaming treatment of coffee can increase preferences of panellists. There were two driving attributes that influence the overall liking of coffee, namely: bitterness and aftertaste. Coffee obtained from the treatment of 60 min steaming was most preferred by panellists. The results of APLSR biplot mapping show that there was a big change in almost all attributes in the coffee samples after 40 min steaming.
ARTICLE | doi:10.20944/preprints201903.0073.v1
Subject: Keywords: coffee culture, domestication, creolization, encapsulation, and middle class
Online: 6 March 2019 (10:48:50 CET)
This article is an anthropology study on how western-style coffee culture influences Indonesian coffee culture and eventually develops a new localized coffee culture. Immense development of such worldwide coffee franchise as Starbucks affects local community's coffee culture, particularly the middle class. This new wave is considered as an alternative lifestyle for those who are consumptive and seeking for leisure, dynamics, and identity. Broader than just the process of domestication or creolization, Indonesian new coffee culture has an element of “soft countering to” western coffee culture even though it still embraces some parts of the western styles. This phenomenon is referred to by the writer as the cultural encapsulation process or the process of substantial cultural resistance by drawing a line between the two coffee cultures with the intention of taking merely compatible elements.
ARTICLE | doi:10.20944/preprints201812.0337.v1
Subject: Social Sciences, Sociology Keywords: drought; coffee farmers; adaptation; coping strategies; central highlands
Online: 28 December 2018 (07:00:52 CET)
Vietnam is the second largest coffee producer in the world, mostly from the Central Highlands region where water has been becoming a scarce resource. Since 2014, drought has been strongly affecting Central Highlands’ agriculture, particularly coffee production. The drought leads to changes in flowering, ripening and thus harvesting times of coffee. Coffee productivity has reduced about 50 percent. Ultimately, coffee quantity and quality is jeopardized which endangers coffee farmers who occupy 90 per cent of population and their livelihoods mainly rely on coffee. Most of coffee farmers have had to develop alternative strategies to respond to the drought. Based on quantitative and qualitative data collected from 50 coffee households in a community in the Central Highlands, this research has indicated that farmers had to find the ways to adapt as well as to cope with drought. The ways of adaptation and coping were diverse, including short, medium and long-term plans. To strengthen the adaptation and coping strategies of farmers with drought in the short term, it is recommended that authorities provide more technical and financial support to farmers. Furthermore, longer term strategies need to focus on land use planning, investment in irrigation schemes, and consolidated afforestation schemes in appropriate areas.
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/preprints201710.0083.v1
Subject: Life Sciences, Biotechnology Keywords: coffee; grape juice; immunosensing; mycotoxins; nanobiosensors; wine; microcantilever
Online: 13 October 2017 (03:42:50 CEST)
Mycotoxins food contamination represents a serious risk for consumers health. They are secondary metabolites of fungi that can be present in a wide range of foodstuffs. Ochratoxin A (OTA) is one of the most toxic compound and it is classified as a possible carcinogenic molecule. The harmful effects of OTA on human and animal health lead to a big boost to develop and optimize highly sensitive and accurate methods for OTA detection. An innovative and rapid detection method based on microcantilever resonators for ochratoxin A identification in food matrix has been developed. This work demonstrates the possibility to apply microcantilever technology in food safety field, showing for the first time in literature the successful detection of one of the most dangerous mycotoxin in different food matrixes both solids and liquids, such as green coffee, grape juice and wine. Sensing performances are discussed in terms of calibration plot and limit of detection.
ARTICLE | doi:10.20944/preprints202204.0145.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Technology; Adoption; Agriculture; Coffee; Smallholder; Extension; Credit; Market; Access
Online: 15 April 2022 (10:44:57 CEST)
The use of improved agricultural technologies has been reported as the major strategy to increase agricultural production, increased household incomes and addressing poverty. However, adoption of such improved technologies by smallholder coffee farmers has been slow and this has contributed to the low coffee productivity in the country and the poor performance of the coffee sub sector. The study was meant to examine the effect of institutional factors including extension services, access to market and access to credit on technology adoption among smallholder coffee farmers in Kanungu District, Uganda. The study collected both quantitative and qualitative data from 289 smallholder coffee farmers and 8 key informants respectively in major coffee growing sub counties in Kanungu district. The study revealed that access to extension services and access to market have a positive significant influence on agricultural technology adoption while access to market has no significant influence on agricultural technology adoption. The study concluded that there is a positive significant relationship between institutional factors and technology adoption among smallholder coffee farmers in Kanungu district.
ARTICLE | doi:10.20944/preprints201912.0124.v1
Subject: Social Sciences, Microeconomics And Decision Sciences Keywords: Data Envelopment Analysis; efficiency; irrigation water; Robusta coffee; Vietnam
Online: 10 December 2019 (03:43:13 CET)
Recent prolonged dry periods and lack of irrigation water have severely affected the productivity of coffee farms’ in the Central Highlands of Vietnam. This paper analyzes the efficiency of irrigation water use for Robusta coffee (Coffea canephora) in Lam Dong province, Highlands, Vietnam. A Cobb-Douglas production function was used to determine coffee productivity’s response to the application of irrigation water and other production factors using data collected from 194 farmers while the Technical Efficiency (TE) and Irrigation Water Use Efficiency (IWUE) were analyzed using a Data Envelopment Analysis (DEA) model. The correlation of different factors to IWUE was determined using the Tobit model. The production function analysis using Cobb-Douglas shows that the volume of irrigation water, amount of working capital, labor and farm size significantly influence coffee productivity. It also shows that indigenous farmers are more efficient in utilizing irrigation water than the (mostly Kinh) migrant farmers. The Tobit result, on the other hand. indicates that farmers’ experience, education level, distance of farm to water source, security of access to water source, extension contact and credit access significantly affect IWUE. The study findings further suggest that mitigating water shortages in coffee farms require sub-regional and national policy support such as better access to credit and extension services, training, land management and household-level effort to improve farming practices, through the application of appropriate technologies and traditional knowledge.
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.
COMMUNICATION | doi:10.20944/preprints201804.0334.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: coffee; temperature; esophageal cancer; thermosensing; sensory thresholds; methodological study
Online: 26 April 2018 (08:05:50 CEST)
The International Agency for Research on Cancer (IARC) evaluates “very hot (>65 °C) beverages” as probably carcinogenic to humans. However, there is a lack of research regarding what temperatures consumers actually perceive as “very hot” or as “too hot”. A methodology for organoleptical assessment of such threshold temperatures was developed. The participants were asked to mix a very hot coffee step by step into a cooler coffee. Because of that, the coffee to be tasted was incrementally getting hotter during the test. The participants took a sip at every addition, until they perceive the beverage as too hot for consumption. The protocol was evaluated using 87 participants. Interestingly, the average pain threshold of the test group (67 °C) and the preferred drinking temperature (63 °C) iterated around the IARC threshold for carcinogenicity. The developed methodology was found as fit for the purpose and may be applied in larger studies.
ARTICLE | doi:10.20944/preprints202103.0446.v1
Subject: Chemistry, Analytical Chemistry Keywords: acrylamide; coffee; partial least square regression; NMR; LC-MS/MS
Online: 17 March 2021 (14:48:40 CET)
Acrylamide is probably carcinogenic to humans (International Agency for Research on Cancer, group 2A) with major occurrence in heated, mainly carbohydrate-rich foods. For roasted coffee, a European Union benchmark level of 400 µg/kg acrylamide is of importance. Regularly, the acrylamide contents are controlled using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). This reference method is reliable and precise but laborious because of the necessary sample clean-up procedure and instrument requirements. This research investigates the possibility of predicting the acrylamide content from proton nuclear magnetic resonance (NMR) spectra that are already recorded for other purposes of coffee control. In the NMR spectrum acrylamide is not directly quantifiable, so that the aim was to establish a correlation between the reference value and the corresponding NMR spectrum by means of a partial least squares (PLS) regression. Therefore, 40 commercially available coffee samples with already available LC-MS/MS data and NMR spectra were used as calibration data. To test the accuracy and robustness of the model and its limitations, 50 coffee samples with extreme roasting degrees and blends were additionally prepared as test set. The PLS model shows an applicability for the varieties C. arabica and C. canephora, which were medium to very dark roasted using drum or infrared roasters. The root mean square error of prediction (RMSEP) is 79 µg/kg acrylamide (n=32). The PLS model is judged as suitable to predict the acrylamide values of commercially available coffee samples. On the other hand, very light roasts containing more than 1000 µg/kg acrylamide are currently not suitable for PLS prediction.
REVIEW | doi:10.20944/preprints201910.0253.v1
Subject: Life Sciences, Biotechnology Keywords: tropical cash crops; coffee; cacao; papaya; chromosome engineering; synthetic biology
Online: 22 October 2019 (05:32:50 CEST)
Background Tropical and subtropical crops such as coffee, cacao, and papaya are valuable commodities and its consumption is a seemingly indispensable part of the daily lives of billions of people across the world. Conventional breeding in these crops is lengthy and yields are threatened by runaway global warming. In this review we propose the application of chromosome engineering and synthetic biology principles in order to enhance synthesis of key metabolites, and transmission of wild traits for resistance to stress and disease. Conclusions It is hoped that the adoption of such technological approaches may enhance the resilience of agricultural communities, lead to economic growth and secure the availability of key resources for generations to come.
ARTICLE | doi:10.20944/preprints201904.0272.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Coffee Output; Climate Change; Commodity Price Volatility; GARCH; ARCH; FMOLS
Online: 24 April 2019 (12:40:21 CEST)
Empirical evidence is lacking on the nexus between coffee commodity output, climate change and commodity price volatility of Africa’s most populous country, Nigeria and other developing countries. To fill this gap, this study analyzed the reaction of coffee output to climate change and commodity price volatility. We used secondary data from 1961 to 2015 from reliable sources for Nigeria. The study adopted GARCH, ARCH and FMOLS in analysis of coffee output reaction to climate change and commodity price volatility. The findings show that coffee output in Nigeria is influenced by climate change and the international commodity price of coffee. The study demonstrates the potential benefits of improving coffee output and export through climate mitigation and adaptation measures and revival of Agricultural Commodity Marketing in Nigeria and other developing countries.
ARTICLE | doi:10.20944/preprints201812.0181.v1
Subject: Social Sciences, Geography Keywords: coffee shop, single origin, connoisseur consumers, sustainable consumption, dynamics capabilities
Online: 17 December 2018 (09:33:49 CET)
Sustainable consumption became the community’s attention as the respond of worrying consumption growth direction that tends to excessively exploit nature without considering the continuity of the next generation. Take into account the growing coffee consumption in Indonesia, this article tries to prove whether the connoisseur consumers (CCs) are capable to mediate dynamics capabilities (DCs) of single origin coffee shops (SOCSs) and to encourage the consumption sustainability. In-depth interview to 30 SOCS managers, 60 baristas and 450 consumers, it is found that CCs are capable of supporting the business continuity of SOCSs because they are loyal consumers with the contribution of more than 20% from the total consumers. Correlation testing between connoisseurs’ attributes and the number of visits also shows positive value. It means there is a significant relationship. In addition, related to the sustainability attribute, the existence of CCs has encouraged the practice of consumption sustainability. At the same time, CCs are capable to moderate SOCSs to improve sensing, seizing, and transforming shop management to put up with the competition. Based on the above findings, CCs are moderating SOCSs in improving their DCs to be more potential in improving the sustainable consumption of coffee commodity in the future.
ARTICLE | doi:10.20944/preprints201707.0086.v1
Subject: Chemistry, Analytical Chemistry Keywords: Caffeine, Uncertainty calculation; ISO 17025, Guatemala coffee grains; GC-FID
Online: 28 July 2017 (13:05:43 CEST)
A simple method for the determination of caffeine in coffee grains by GC-FID is presented in the current work. The method was fully validated according to ISO 17025 requirements and European Commission regulation. The accuracy, as provided by recovery experiments was higher than 93%, and the precision, as provided by the (%)Relative standard deviation under reproducibility conditions, was lower than 5%. All independent parameters that lead in the increase of methods uncertainty were investigated. In the present work all special precautions were taken into account in order to avoid the use of an internal standard. The method was applied in real samples and possible health claims were investigated.
ARTICLE | doi:10.20944/preprints202203.0299.v1
Subject: Life Sciences, Other Keywords: Biomass; Carbon pool; Indigenous agroforestry system; Coffee; Enset; South-eastern Ethiopia
Online: 22 March 2022 (10:51:01 CET)
The role of agroforestry systems in providing ecosystem services is very crucial. The most significant increase in carbon (C) storage is often achieved by moving from lower biomass land-use systems to tree-based systems like agroforestry (AF). However, estimation of carbon stocks in indigenous agroforestry systems of South-eastern Rift- valley landscapes, Ethiopia the data are scarce. The study was aimed to investigate the biomass, biomass carbon (BC), and soil organic carbon (SOC) stock of Enset based, Enset-Coffee based, and Coffee-Fruit tree-Enset based agroforestry systems. Comparison of SOC stock of agroforestry systems against their adjacent monocropping farms was also investigated. The study was conducted in three selected sites of the Dilla Zuria district of Gedeo zone. Twenty farms (total of 60) representative of each AF system were randomly selected, inventoried and biomass C stocks estimated. Ten adjacent mono-cropping farms which were related to each AF system were selected in a purposive manner for comparison of SOC stock. Inventory and soil sampling were employed in the 10×10 m farm plot. The mean aboveground biomass ranged from 81.1 t ha-1 to 255.9 t ha-1 and for belowground biomass from 26.9 t ha-1 to 72.2 t ha-1. The highest C stock was found in Coffee-Fruit tree-Enset based (233.3±81.0 t ha-1), and the lowest was in Coffee-Enset based agroforestry system (190.1±29.8 t ha-1). The result showed that SOC stocks were not statistically significant between the three AF systems, although they showed a significant difference in their BC stock. The AF systems' C stocks are substantially higher than those reported for tropical forests and other AF systems. The SOC of AF systems was significantly higher than the ones for the adjacent monocropped farms. Therefore, it is possible to deduce that AF systems are storing significant amount of C and contributing to climate change mitigation.
ARTICLE | doi:10.20944/preprints202110.0428.v1
Subject: Materials Science, Polymers & Plastics Keywords: evaporation; poly (vinylidene fluoride); crystallization; droplet; coffee ring effect; ultrasonic spray
Online: 28 October 2021 (09:55:59 CEST)
The evaporation of polymer solution droplet is an important in solution-based polymer film fabrications, such as inkjet print, spray coatings, and droplet casting etc. In this work, we investigated the effect of droplet size, solvent evaporation rate, and concentration on “coffee-ring” effect, crystal nucleation, polymorphism, and morphology of dried poly (vinylidene fluoride) (PVDF) solution droplets with atomic force microscopy (AFM) method. We found that the crystal structure, morphology and crystal distribution in the center and edge regions of dried PVDF droplets were different due to “coffee-ring” effect. The “coffee-ring” effect of dried PVDF droplets was mainly composited of accumulated crystals at the edge region of droplet, which was mainly made by crystallization of migrated chains. The interplay between migration of chains, crystallization and solidification of PVDF droplets significantly influenced the formation of “coffee-ring”. In addition, our results showed that the decrease of droplet size and controlling solvent evaporation rate were effective ways to improve the PVDF β-phase nucleation and decrease crystal size.
ARTICLE | doi:10.20944/preprints202009.0616.v1
Subject: Physical Sciences, Condensed Matter Physics Keywords: interfacial crystallization; liquid marble, hydrophobic particle; superhydrophobic surface; coffee-stain effect.
Online: 25 September 2020 (15:30:00 CEST)
We report interfacial crystallization in droplets of saline solutions placed on superhydrophobic surfaces and liquid marbles filled with the saline. Evaporation of saline droplets deposited on superhydrophobic surface resulted in the formation of cup-shaped millimeter-scaled residues. The formation of the cup-like deposit is reasonably explained within the framework of the theory of the coffee-stain effect, namely, the rate of heterogeneous crystallization along the contact line of the droplet is many times higher than in the droplet bulk. Crystallization within evaporated saline marbles, coated with lycopodium particles, depends strongly on the evaporation rate. Rapidly evaporated saline marbles yielded dented shells built of a mixture of colloidal particles and NaCl crystals. We relate the formation of these shells to the interfacial crystallization promoted by hydrophobic particles coating the marbles, accompanied with the upward convection flows supplying the saline to the particles, serving as the centers of interfacial crystallization. Convective flows prevail over the diffusion mass transport for the saline marbles heated from below.
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.
COMMUNICATION | doi:10.20944/preprints201908.0192.v1
Subject: Chemistry, Applied Chemistry Keywords: caffeine; colloidal coffee; optical absorption; pH sensor; solute-solvent interactions; UV absorber
Online: 19 August 2019 (04:14:30 CEST)
Coffee and caffeine have been used as solar absorbers and also to increase the thermal stability and efficiency of perovskite solar cells. In this work, we report the sensing of extremely alkaline pH by colloidal coffee solution aided by generation of an optical absorption band in the near-UV region. This generation of absorption band could be explained by the orientation induced dipole-dipole interactions arising from differing caffeine-solvent interactions with varying pH. Such a generation leads to the lowering of direct as well as indirect bandgaps from 4 eV-->2.8 eV& 3.4 eV-->2.5 eV, respectively. We also estimate the changes in optical energy storage efficiency, inferring it to be highest for pH 11 having the highest intensity of the generated absorption band (λ_abs≈360 nm). With these observations and further deductions, the work reported in this paper would be of immense interest to the researchers working in the field of development of chemical pH sensors and also in the development of novel UV absorbers.
REVIEW | doi:10.20944/preprints201807.0467.v1
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: caffeine; coffee; epidemiology; recall bias; misclassification; residual confounding; reverse causation; publication bias
Online: 25 July 2018 (05:57:48 CEST)
Consumption of coffee by women early in their pregnancy has been viewed as potentially increasing the risk of miscarriage, low birth weight, and childhood leukemias. Many of these reports of epidemiologic studies have not acknowledged the potential biases inherent in studying the relationship between early-pregnancy-coffee consumption and subsequent events. I discuss five of these biases, recall bias, misclassification, residual confounding, reverse causation, and publication bias. Each might account for claims that attribute adversities to early-pregnancy-coffee consumption. To what extent these biases can be avoided remains to be determined. At a minimum, they need to be acknowledged wherever they might account for what is reported.
REVIEW | doi:10.20944/preprints202212.0138.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Spent coffee grounds; SCG Briquettes; SCG Biodiesel; Caffeine; Residual Oil; Irregular Particle Size
Online: 8 December 2022 (01:42:06 CET)
Coffee is regarded as the highly consumed beverage throughout the world and has established a key spot in the world economy as an important commodity for trading. In general, they are produced by brewing their roasted and ground beans, which release aromatic coffee; as well as produce an equivalent amount of spent coffee grounds (SCG). Previously, they were discarded as wastes or used as natural pest repellent or garden fertilizer; however, in recent times, are valorized into biofuels owing to their high calorific value. In fact, SCG briquettes have gained wide attention for supplying energy renewably, especially to the rising energy demand; and also have been identified as an effective measure to reduce their pollution. With this in mind, this present chapter focuses on reviewing the availability and chemistry involved in these SCG wastes, pre-treatments and preparations required for their briquetting, compacting techniques followed, and fuel characteristics of their briquettes, from various available works of literature. Here, their availability showcases the amount of SCG wastes generated with respect to time and consumption, wherein understanding their chemistry helps in deciding the pre-treatments necessary for their briquetting. Meanwhile, preparation techniques briefs about the necessary pre-treatments undertaken before compaction by different researchers; and the fuel characteristics define the physicochemical and mechanical properties of their briquettes, developed using various compaction methods. Besides, combustion behaviors of these briquettes are explained in terms of their burning characteristics and emission levels, as reported in literatures; which help in deciding their suitability as a replacement for existing fossil coal. Eventually, all the reported data were in accordance with their permissible standards and suggested these SCG as a highly renewable solid biofuel.
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.
COMMUNICATION | doi:10.20944/preprints202212.0070.v1
Subject: Life Sciences, Other Keywords: diester chlorogenoborate complex; green coffee bean; HPTLC/UV; HPTLC/ESI–MS; UHPLC/MS; FTIR
Online: 5 December 2022 (09:08:41 CET)
The natural compounds of boron have many applications, including as dietary supplement. Communication is based on the discovery that diester chlorogenoborate complex can be detected and quantified from green coffee bean. The study reports that such diester molecule can also be synthesized in stable form by direct reaction of boric acid and chlorogenic acid, in a mixture of acetonitrile–water (1:1, v/v), left to evaporate over a period of 48 hours, at room temperature, resulting a spirocyclic form (diester complex). The diester complex, with its molecular structure and digestibility attributes has potential application as prebiotic in gut health, oral health and as micronutrient essential for microbiota to human and animals.
ARTICLE | doi:10.20944/preprints202103.0158.v1
Subject: Chemistry, Analytical Chemistry Keywords: coffee; cold brew; nitro cold brew; roasting; extraction; hygiene; risk assessment; NMR; sensory analysis
Online: 4 March 2021 (12:29:53 CET)
Cold brew coffee is a new trend in coffee industry. This paper presents pilot studies into several aspect of this beverage. Using an online survey, the current practices of cold brew coffee preparation were investigated identifying a rather large variability with a preference for extraction of medium roasted Arabica coffee using 50-100 g/l at 8°C for about 1 day. Sensory testing using ranking and triangle tests showed that cold brew may be preferred over iced coffee (cooled down hot extracted coffee). Extraction experiments at different conditions combined with nuclear magnetic resonance (NMR) analysis showed that the usual extraction time may be longer than necessary as most compounds are extracted within only a few hours, while increasing turbulence (e.g. using ultrasonication) and temperature may additional increase the speed of extraction. NMR analysis also revealed a possible chemical differentiation between cold brew and hot brew using multivariate data analysis. Decreased extraction time and reduced storage times could be beneficial for cold brew product quality as microbiological analysis of commercial samples detected samples with spoilage organisms and contamination with Bacillus cereus.
ARTICLE | doi:10.20944/preprints202003.0056.v1
Subject: Life Sciences, Other Keywords: Hermetia illucens prepupae; Black soldier fly; coffee silverskin; microalgae; toxic metals; bioaccumulation; chemical hazard
Online: 4 March 2020 (09:48:16 CET)
Among other species, Black Soldier Fly (Hermetia illucens, HI, Diptera, Stratiomydae) has the great potential as food and feed ingredient in the EU, particularly thanks to its preference for organic waste as growth substrate. The production of insects as livestock feed or as food ingredient requires a strict monitoring of heavy metal content in the growth substrate in order to secure its safe. This study aims to investigate the presence of toxic metals cadmium, lead, mercury, arsenic, and nickel in HI prepupae and their growth substrates based on coffee roasting by-product and microlagae Schizochytrium sp. and Isochrysis sp. Analyses were carried out via graphite furnace atomic absorption spectrophotometry for Cd, Pb, Ni, and As, and via Direct Mercury Analyzer for Hg. All metal concentrations found in growth substrates were below the legal limit of undesirable substances in animal feed (2002/32/EC). Metals concentrations in HI prepupae were in the range (mg kg-1 wet weight): Cd 0.072–0.084, Pb 0.018–0.026, Hg 0.010–0.032, As 0.036–0.047, Ni 0.18–0.76. HI prepupae accumulate Cd, Pb and Hg, but our results indicate that the risk of exposure to metals from consumption of HI prepupae is relatively low and in compliance with European Union regulations.
ARTICLE | doi:10.20944/preprints201811.0078.v2
Subject: Social Sciences, Economics Keywords: market segmentation; coffee market; consumer behaviour; sustainable consumption; sustainable values; factor analysis; cluster analysis
Online: 27 November 2018 (05:19:25 CET)
The driving force behind adopting the idea of sustainable development are producers and retailers. Unfortunately, when preparing their product range for consumers, many of them still only pay attention to the size of the customers’ earnings, how often they shop and how much they buy when shopping. In consumer segmentation, sustainable values that consumers apply when making their purchasing decisions are rarely taken into account. The aim of this article is to show that values such as environmental protection, the ethical behaviour of producers, fair trade or maximising the utility function of consumption are so important in the purchasing process in the coffee market that they can be used as segmentation variables. The Polish coffee market was selected to carry out segmentation taking into account the consumers' sustainable values. The main source of the article is the results of a standardized online survey conducted on a nationwide sample of 800 coffee consumers in July 2018. Multi-dimensional analyses such as extrapolative factor analysis (EFA) and cluster analysis (CA) were used to describe the obtained results. As a result, six segments of coffee consumers were identified and described: “responsible, aspiring to be connoisseurs”, “loyal coffee enthusiasts”, “pragmatic users”, “coffee laypersons”, “sophisticated connoisseurs”, “consumerists, connoisseurs, but not at any price”. Among the identified segments, the sustainable consumption values most often mentioned refer to "responsible, aspiring to be connoisseurs", and the least often - ”consumerists, connoisseurs, but not at any price”. The conclusions presented in the last part of the article may be used by manufacturing and trade enterprises, operating on the coffee market, in order to respond to the identified needs and expectations of consumers and by governmental and social organisations so as to determine the directions of pro-ecological education of consumers.
ARTICLE | doi:10.20944/preprints201710.0164.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: coffee; dietary supplements; metabolic syndrome X; non-alcoholic fatty liver disease; adiponectin; hyperpolarized magnetic resonance spectroscopy
Online: 27 October 2017 (02:32:43 CEST)
Since coffee has been shown to influence positively the metabolism of subjects with metabolic syndrome (MetS), we aimed to evaluate the short- and long-term effects of a coffee-based supplement on different features of diet-induced MetS. 24 Sprague Dawley rats were divided into control or nutraceuticals groups to receive a high-fat/high fructose diet with or without a mixture of caffeic acid (30 mg/day), trigonelline (20 mg/day), and cafestol (1 mg/day) for 12 weeks. An additional 11 rats were assigned to an acute crossover study. In the chronic experiment, nutraceuticals did not alter body weight or glycemic control but improved fed hyperinsulinemia and HOMA-IR, and plasma adiponectin levels. The impact of nutraceuticals on post-prandial glycemia tended to be more pronounced after acute administration than at the end of the chronic study. Circulating and intrahepatocellular alanine transaminase activity, assessed by hyperpolarized-13C NMR spectroscopy, were reduced by coffee nutraceuticals at endpoint. There was also a tendency towards lower liver triglyceride content and histological steatosis score in the intervention group. In conclusion, a mixture of coffee nutraceuticals improved insulin sensitivity and exhibited hepatoprotective effects in a rat model of MetS. Higher dosages with or without caffeine deserve to be studied in the future.
ARTICLE | doi:10.20944/preprints201810.0537.v1
Subject: Social Sciences, Marketing Keywords: emotion; commitment; brand loyalty; willingness to pay more; coffee quality; service quality; physical environment quality; price fairness
Online: 23 October 2018 (11:58:03 CEST)
: Following the phenomenal growth of and competition among coffee chain retailers, the coffee chain market has expanded substantially thanks to rising income levels, the increasing young population, and rapidly changing lifestyles. Attracting consumers’ attention and enhancing their loyalty behaviors have become very difficult for coffee chain retailers. This study seeks to understand the mechanisms through which emotions and the dedication-constraint model lead to brand loyalty and willingness to pay more to certain coffee chain retailers. Emotions and the dedication-constraint model are major factors in the research, but few studies have combined them to examine the formation of loyalty behaviors. This study synthesizes emotional responses and the dedication-constraint model to develop a theoretical model. Based on the ambivalent view of emotions, it also examines how positive and negative emotions affect the combination of brand loyalty and willingness to pay more to certain coffee chain retailers. Moreover, it identifies the antecedents of affective and calculative commitments in the context of coffee chain retailers. Our findings indicate that loyalty behaviors (dedication- and constraint-based mechanisms from brand loyalty and willingness to pay more to certain coffee chain retailers), emotional responses, and affective and calculative commitments significantly affect brand loyalty directly and indirectly through both positive and negative emotions. Furthermore, service quality, physical environment quality, and price fairness significantly affect affective commitments, while price fairness significantly affects both affective and calculative commitments. Finally, affective and calculative commitments significantly affect willingness to pay more, both directly and indirectly, through positive emotions and affect it directly through negative emotions. The results’ theoretical and managerial implications and possible future research directions are discussed.
ARTICLE | doi:10.20944/preprints201808.0365.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: coffee; insulin resistance; metabolic syndrome X; Non-alcoholic fatty liver disease; Carbon-13 magnetic resonance spectroscopy; phytotherapy
Online: 21 August 2018 (04:38:00 CEST)
Literature is inconsistent as to how coffee affects the features of the metabolic syndrome (MetS), and which bioactive compounds are responsible for its metabolic effects. We aimed to compare the in-vivo effects of unfiltered coffee with a selected mixture of its compounds on diet-induced MetS. 24 male Sprague-Dawley rats were fed a high-fat (35% W/W) food plus 20% W/W fructose in drinking water for 14 weeks, and were randomized into three groups: control, coffee, or nutraceuticals (5-O-caffeoylquinic acid, caffeic acid, and trigonelline). Coffee or nutraceuticals were provided in drinking water in a dosage equal to 4 cups/day in a human. Compared to the controls, only coffee supplementation decreased total food intake, weight gain, and estimated average plasma glucose. Surrogate measures of insulin resistance (fasting insulin, HOMA-IR, and oral glucose tolerance) were improved at endpoint in the coffee group. Circulating triglyceride levels were also reduced by coffee. Histopathological and quantitative measurements indicated lower grades of liver steatosis after long-term coffee consumption. In conclusion, a combination of phenolic acids and trigonelline was not as effective as coffee per se in improving the components of the MetS. This points to the role of other coffee chemicals and a potential synergism between compounds.