ARTICLE | doi:10.20944/preprints202004.0152.v1
Subject: Keywords: citrus fruits; coronavirus; COVID-19; flavonoids; hesperetin; hesperidin; hydrodynamic cavitation; pectin; SARS-CoV-2.
Online: 9 April 2020 (12:47:09 CEST)
Based on recent computational and experimental studies, hesperidin, a bioactive flavonoid abundant in citrus peel, stands out for its high binding affinity to the main cellular receptors of SARS-CoV-2, outperforming drugs already recommended for clinical trials. Thus, it is very promising for prophylaxis and treatment of COVID-19, along with other coexistent flavonoids such as naringin, which could help restraining the pro-inflammatory overreaction of the immune system. Controlled hydrodynamic cavitation processes showed the highest speed, effectiveness and efficiency in the integral and green aqueous extraction of flavonoids, essential oils and pectin from citrus peel waste. After freeze-drying, the extracted pectin showed high quality and excellent antioxidant and antibacterial activities, attributed to flavonoids and essential oils adsorbed and concentrated on its surface. This study reviews the recent evidence about hesperidin as a promising molecule, and proposes a feasible and affordable process based on hydrodynamic cavitation for the integral aqueous extraction of citrus peel waste resulting in hesperidin-rich products, either aqueous extracts or pectin tablets. The uptake of this process on a relevant scale is urged, in order to achieve large-scale production and distribution of hesperidin-rich products. Meanwhile, experimental and clinical studies could determine the effective doses either for therapeutic and preventive purposes.
ARTICLE | doi:10.20944/preprints202003.0386.v1
Subject: Life Sciences, Virology Keywords: hesperidin; COVID-19; pectin; flavonoids; hydrodynamic cavitation; IntegroPectin
Online: 26 March 2020 (13:59:28 CET)
Computational studies suggest that hesperidin, a flavonoid abundant in citrus peel, binding the three main cellular receptors of SARS-CoV-2 virus can act in the prophylaxis and treatment of COVID-19. Herein we urge the uptake of hydrodynamic cavitation industrial-scale reactors based on the low cost, reliable Venturi tube for the extraction of citrus pectin rich in hesperidin (and in other bioflavonoids including naringing) by very fast processing of waste orange peel or waste lemon peel in water only. A device able to process up to 500 kg of waste peels per session, similar to the one lately deployed in Italy for hydrodynamic cavitation-assisted brewing, is capable to provide 36,000 doses of 1000 mg hesperidin per day.
ARTICLE | doi:10.20944/preprints201911.0246.v1
Subject: Life Sciences, Biochemistry Keywords: bioactive compounds; forest air; forest bathing; forest therapy; hiking trails; human health; monoterpenes; stress; volatile organic compounds
Online: 21 November 2019 (04:19:17 CET)
Forest healing effects are increasingly valued for their contribution to human psychological and physiological health, motivating further advances aimed at improving the knowledge of the relevant forest resources. Biogenic volatile organic compounds, emitted by the plants and accumulating in the forest atmosphere, are essential contributors to the forest healing effects, and represent the focus of this study. Using a photoionization detector, we investigated the high frequency variability, in time and space, of the concentration of total volatile organic compounds, on a hilly site, as well as along forest paths and long hiking trails on Italian northern Apennines. The scale of concentration variability was found to be comparable to absolute concentration levels, within time scales of less than one hour, and spatial scales of several hundred meters. During daylight hours, the concentration peaked from noon to early afternoon, followed by early morning, with lowest levels in late afternoon. Based on a conceptual model, these results were related to meteorological variables, including the atmospheric vertical stability profile. Moreover, preliminary evidence pointed to higher concentration of volatile organic compounds in forests dominated by conifer trees, in comparison with pure beech forests.
ARTICLE | doi:10.20944/preprints201812.0175.v1
Subject: Life Sciences, Biotechnology Keywords: Abies Alba Mill.; antioxidant activity; coniferous trees; essential oils; flavonoids; food preservation; green extraction; hydrodynamic cavitation; nutraceutics; polyphenols
Online: 17 December 2018 (07:07:56 CET)
Extracts from parts of coniferous trees have received increased interest due to their valuable bioactive compounds and properties, useful for plenty of experimental and consolidated applications, in fields comprising nutraceutics, cosmetics, pharmacology, food preservation, and stimulation of plant growth. However, the variability of the bioactive properties, the complexity of the extraction methods, and the use of potentially harmful synthetic chemicals, still represent an obstacle to the spreading of such valuable natural compounds. Hydrodynamic cavitation is emerging as a promising innovative technique for the extraction of precious food components and by-products from waste raw material of the agro-food production chain, which can improve processing efficiency, reduce resource consumption, and produce healthy, high-quality products. In this study, a process based on controlled hydrodynamic cavitation was applied for the first time to the production of aqueous solutions of silver fir (Abies Alba Mill.) needles with enhanced antioxidant activity. The observed levels of the in vitro antioxidant activity, comparable or higher than those found for reference substances, pure extracts, and other water extracts and beverages, highlight the very good potential of the HC process for the creation of solvent-free, aqueous solutions endowed with bioactive compounds extracted from silver fir needles.
CONCEPT PAPER | doi:10.20944/preprints202102.0266.v1
Online: 10 February 2021 (16:18:39 CET)
Produced in many world’s countries at over 1 million tonne/year rate by extraction of certain woods and barks with boiling water, tannin is a class of high molecular weight biophenols increasingly used in a number of industries. This study offers a new bioeconomy insight into an old natural product that, we argument in this study, will play a crucial role in the development of the bioeconomy of forest regions. After providing an updated picture of key economic and production aspects, we show how flourishing research on tannin’s biological activity and technological applications has revealed many new properties which are likely to drive significant growth in demand in the near and mid-term future. The study concludes with selected recommendations for bioeconomy scholars and for policy-makers based in forest areas.
ARTICLE | doi:10.20944/preprints202101.0160.v1
Subject: Chemistry, Applied Chemistry Keywords: cellulose; lemon; grapefruit; citrus processing waste; hydrodynamic cavitation; bioeconomy
Online: 8 January 2021 (13:25:17 CET)
Named herein “CytroCell”, the cellulosic material obtained via hydrodynamic cavitation of citrus processing waste in water is cellulose of low crystallinity, high porosity, good water holding capacity and good dispersibility in water. These properties, here demonstrated for the first time for lemon and grapefruit CytroCell, open the route to mass scale production of a useful functional material from a cheap and abundant biowaste. The process, indeed, does not require any pre-treatment of the raw material, and does not use acid, alkali, chemical oxidants or enzymes.
ARTICLE | doi:10.20944/preprints202208.0342.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: Citrus flavonoids; naringin; naringenin; pectin; byproducts; anti-ischemic myocardial protection; hydrodynamic cavitation
Online: 18 August 2022 (10:54:33 CEST)
Citrus flavonoids are well-known for beneficial effects at the cardiovascular and cardio-metabolic level, but often the encouraging in vitro results are not confirmed by in vivo approaches; also clinical trials are inconsistent. The limited bioavailability of them can be, at least in part, the reason of these discrepancies. Therefore many efforts were performed towards the improvement of their bioavailability. Hydrodynamic cavitation methods were successfully applied to the extraction of byproducts of the Citrus fruits industry, showing high process yields and affording stable phytocomplexes, known as IntegroPectin, endowed with great amounts of bioactive compounds and high water solubility. Cardioprotective effects of grapefruit IntegroPectin were evaluated by an ex vivo ischemia/reperfusion protocol. A further pharmacological characterization was carried out to assess the involvement of mitochondrial potassium channels. Grapefruit IntegroPectin, where naringin represented 98% of flavonoids, showed anti-ischemic cardioprotective activity, better than pure naringenin (the bioactive aglycone of naringin). On cardiac isolated mitochondria, this extract confirmed that naringenin/naringin were involved in the activation of mitochondrial potassium channels. The hydrodynamic cavitation-based extraction confirmed a valuable opportunity for the exploitation of Citrus fruits waste, with the end product presenting high levels of Citrus flavonoids and an improved bioaccessibility that enhances its nutraceutical and economic value.
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/preprints202008.0106.v1
Subject: Life Sciences, Microbiology Keywords: citrus pectin; lemon; grapefruit; IntegroPectin; flavonoids; citrus terpenes; polyphenols; antimicrobial resistance; Staphylococcus aureus; Pseudomonas aeruginosa
Online: 5 August 2020 (03:34:49 CEST)
Grapefruit and lemon pectin obtained from the respective waste citrus peels via hydrodynamic cavitation in water only are powerful, broad-scope antimicrobial alternatives to antibiotics against Gram-negative and -positive pathogens. Dubbed IntegroPectin, these pectic polymers functionalized with citrus flavonoids and terpenes show superior antimicrobial activity when compared to commercial citrus pectin. Similarly to commercial pectin, lemon IntegroPectin determined ca. 3 log reduction of Staphylococcus aureus cells, while an enhanced activity of commercial citrus pectin was detected in the case of Pseudomonas aeruginosa cells with a minimal bactericidal concentration (MBC) of 15 mg mL-1. Although grapefruit and lemon IntegroPectin share equal MBC in the case of P. aeruginosa cells, grapefruit IntegroPectin shows boosted activity upon exposure of S. aureus cells with a 40 mg mL-1 biopolymer concentration being sufficient to achieve complete killing of the bacterial cells. Insight on the mechanism of action of these biocompatible antimicrobials and their effect on bacterial cells, at the morphological level, were obtained indirectly through Fourier Transform Infrared spectroscopy and directly through scanning electron microscopy. In the era of antimicrobial resistance, these results are of great societal and sanitary relevance as they open new avenues to develop innovative antimicrobials for the treatment of polymicrobial infections unlikely to develop drug resistance.
ARTICLE | doi:10.20944/preprints202001.0157.v3
Subject: Life Sciences, Biochemistry Keywords: pectin; antioxidant; lemon; flavonoids; hydrodynamic cavitation; IntegroPectin
Online: 31 March 2020 (05:00:13 CEST)
Lemon pectin extracted along with water-soluble flavonoids and other phytochemicals from citrus industry’s waste lemon peel via hydrodynamic cavitation in water, directly at pre-industrial scale and further isolated via freeze drying, shows exceptionally high antioxidant and non-cytotoxic activity. Preliminary investigation indicates also significant antimicrobial activity. These findings open the route to the development of new nutraceutical and healthcare application of a versatile biopolymer endowed with new functionality, rapidly and conveniently obtained from an abundant by-product of the agrofood industry.
ARTICLE | doi:10.20944/preprints202003.0263.v1
Subject: Life Sciences, Microbiology Keywords: pectin; antibacterial; lemon; flavonoids; hydrodynamic cavitation; IntegroPectin
Online: 17 March 2020 (03:43:39 CET)
Pectin extracted via hydrodynamic cavitation in water only from waste lemon peel and further isolated via freeze drying displays significant antibacterial activity against Staphylococcus aureus, a Gram positive pathogen which easily contaminates food. The antibacterial effect of the new IntegroPectin is largely superior to that of commercial citrus pectin, opening the way to advanced applications of a new bioproduct now obtainable in large amounts and at low cost from citrus juice industry’s waste.
ARTICLE | doi:10.20944/preprints202012.0034.v1
Subject: Chemistry, Applied Chemistry Keywords: IntegroPectin, lemon, grapefruit, pectin, waste citrus peel, -terpineol, hydrodynamic cavitation, circular economy
Online: 1 December 2020 (15:07:35 CET)
The HS-SPME GC-MS analysis of the volatile compounds adsorbed at the outer surface of lemon and grapefruit pectins obtained via hydrodynamic cavitation of industrial waste streams of lemon and grapefruit peels in water only suggests important new findings en route to understanding the powerful and broad biological activity of these new pectic materials. In agreement with the ultralow degree of esterification of these pectins, the high amount of highly bioactive α-terpineol and terpinen-4-ol points to limonene decomposition catalyzed by residual citric acid in the citrus waste peel residue of the juice industrial production.
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/preprints202105.0485.v1
Subject: Behavioral Sciences, Applied Psychology Keywords: anger; anxiety; confusion; depression; fatigue; forest therapy; mental health; vigor; volatile organic compounds
Online: 20 May 2021 (11:22:20 CEST)
Immersion in forest environments was shown to produce beneficial effects to human health, in particular psychophysical relaxation, so much that this practice is increasingly recognized as a form of integrative medicine. Limited evidence exists about both statistical significance and size of the effects conditioned on personal characteristics, as well as on the main external variables. The primary purpose of this study was to substantiate the very concept of forest therapy by means of the quantification and significance of the psychological effects, stratified by gender, age groups and place of residence. A preliminary qualitative analysis of the main determinants, in particular the method of conducting, the meteorological comfort and the concentration of volatile organic compounds in the forest atmosphere, was afforded. Seven forest therapy sessions were performed in late summer though early fall, resulting in 150 psychological self-assessment questionnaires administered before and after each session. The results were comparable or even better than others reported in the international literature. Moreover, preliminary evidence arose about different functionality towards specific psychological indexes conditioned at least on gender and age groups, as well as meteorological comfort, structured programs and, possibly, volatile organic compounds showed an impact on the outcomes.
ARTICLE | doi:10.20944/preprints202008.0707.v1
Subject: Behavioral Sciences, Cognitive & Experimental Psychology Keywords: Anxiety; Audio-Visual stimulation; COVID-19; Environmental enrichment; Forest environments; Forest therapy; Lockdown; Mental health; Stress; Quarantine
Online: 31 August 2020 (05:20:50 CEST)
The prolonged lockdown imposed to contain the COVID-19 pandemic prevented many people from direct contact with nature and greenspaces, raising alarms for a possible worsening of mental health. This study investigates the effectiveness of a simple and affordable remedy for improving psychological well-being, based on audio-visual stimuli brought by a short computer video showing forest environments, with an urban video as a control. Randomly selected participants were assigned the forest or urban video, to look at and listen early in the morning, and filled questionnaires. In particular, the State-Trait Anxiety Inventory (STAI) Form Y, collected in baseline condition and at the end of the study, and the Part II of the Sheehan Patient Rated Anxiety Scale (SPRAS), collected every day immediately before and after watching the video. The virtual exposure to forest environments showed effective to reduce perceived anxiety levels in in people forced by lockdown in limited spaces and environmental deprivation. Although significant, the effects were observed only in the short term, highlighting the limitation of the virtual experiences. The reported effects might also represent a benchmark to disentangle the determinants of health effects due to real forest experiences, for example, the inhalation of biogenic volatile organic compounds (BVOC).