•Extraction of polyphenols from grapefruit peels using green solvents.•Intensification of extraction using High Voltage Electrical discharges (HVED).•Deep eutectic solvents and aqueous glycerol ...enhanced the extraction of polyphenols.•The addition of glycerol has reduced the energy of the pre-treatment by 6 times.•Solubility of naringin was estimated through a modelling of its Hansen parameters.
Deep eutectic solvents (DES) and aqueous glycerol were proposed as green alternatives to conventional solvents for the extraction of polyphenols from grapefruit peels. In order to increase the extraction kinetics and yields of polyphenols, high voltage electrical discharges (HVED) were used as a pre-treatment technology (energy varied between 7.27 and 218 kJ/kg). Results showed that the HVED energy input can be reduced, when the subsequent solid-liquid extraction was performed in 20% (w/v) aqueous glycerol or in DES (lactic acid: glucose) instead of water. The addition of glycerol has reduced the energy of the pre-treatment by 6 times. The same diffusivity of polyphenols (4 × 10−11 m2/s) was obtained in water from HVED pre-treated peels at 218 kJ/kg and in aqueous glycerol from pre-treated peels at 36 kJ/kg. The solubility of naringin, the main flavonoid compound of grapefruit peels in the solvents, was investigated through a theoretical modelling of its Hansen solubility parameters.
The impact of pulsed electric field (PEF) treatment on orange, pomelo, and lemon in aqueous media was studied. Whole fruits and stack of peels were PEF treated at electric field strength of 3kV/cm ...and 10kV/cm, respectively. The PEF induced damage of the whole fruit was evaluated by different disintegration indexes. The PEF treatment increased the yield of juice obtained after pressing by 25% for orange, 37% for pomelo, and 59% for lemon. The effect of PEF on different parts of each fruit was studied. Flavedo and albedo were separated from the untreated fruit or PEF treated fruit and solvent extraction (1/1 ethanol/water solution) of polyphenols was conducted. The quantification and characterization of polyphenols in each part was compared for untreated and PEF treated fruit. The application of high electric field strength on orange peels enhanced the extraction of polyphenols up to 22mgGAE/g DM.
Citrus fruits are valuable sources of bioactive compounds (vitamins, antioxidants, carotenoids and flavonoids) and their processing represents an industrial importance. An application of PEF to whole fruits may be useful for improving the efficiency of juice extraction from different citrus fruits. The concentration of polyphenols in the extracted juice could be significantly enhanced by the treatment of citrus peels with PEF at high electric field strength.
•Pulsed electric fields (PEF) were applied on whole citrus fruits at 3kV/cm.•Significant increase in juice yields and polyphenols in juice was obtained.•PEF treatment was applied on stack of orange peels at 10kV/cm.•Significant increase of polyphenols extraction from PEF treated peels was observed.•PEF treatment improved extraction of polyphenols in 50% ethanol solution.
Polyphenols have attracted huge interest among researchers of various disciplines because of their numerous biological activities, such as antioxidative, antiinflammatory, antiapoptotic, cancer ...chemopreventive, anticarcinogenic, and antimicrobial properties, and their promising applications in many fields, mainly in the medical, cosmetics, dietary supplement and food industries. In this review, the latest scientific findings in the research on polyphenols interaction with the microbiome and mitochondria, their metabolism and health beneficial effects, their involvement in cognitive diseases and obesity development, as well as some innovations in their analysis, extraction methods, development of cosmetic formulations and functional food are summarized based on the papers presented at the 13th World Congress on Polyphenol Applications. Future implications of polyphenols in disease prevention and their strategic use as prophylactic measures are specifically addressed. Polyphenols may play a key role in our tomorrow´s food and nutrition to prevent many diseases.
Beneficial effects of polyphenols and their metabolites, and their potential application in cosmetics, food, and health.
In this study, polyphenols were extracted from pomegranate peels with solid-liquid (SL), ultrasound (US) and Ired-Irrad®, a newly-patented infrared (IR) extraction technique. Deep eutectic solvents ...were used as green alternatives to conventional aqueous or organic solvents. The extraction process was conducted at 50 °C for 90 min. The biological (antiradical, antioxidant, antimicrobial and antifungal) activities of the polyphenols extracted in different solvents with the above-mentioned extraction methods were compared. The highest concentration of polyphenols (152 mg/g DM) was obtained with IR in the deep eutectic solvent. The extraction in the deep eutectic solvents using the IR technique gave the highest antioxidant and antiradical activities. Polyphenols extracts allowed the inhibition of gram-positive and gram-negative bacteria up to 87% and 95% respectively. They also inhibited the growth of the fungus Aspergillus flavus by 46%. High performance liquid chromatography (HPLC) permitted the identification and quantification of the extracted polyphenols. The solvent and the method of extraction had a high selectivity on the extraction of polyphenols.
•The extraction of polyphenols from pomegranate peels was intensified.•Deep eutectic solvents (DES) were used as green solvents.•Ired-Irrad® a newly-patented infrared (IR) extraction technique was tested.•The biological activities of the polyphenols were determined.•Highest biological activities of extracted polyphenols were obtained with IR in DES.
Citrus genus is a prominent staple crop globally. Long-term breeding and much hybridization engendered a myriad of species, each characterized by a specific metabolism generating different secondary ...metabolites. Citrus aurantium L., commonly recognized as sour or bitter orange, can exceptionally be distinguished from other Citrus species by unique characteristics. It is a fruit with distinctive flavor, rich in nutrients and phytochemicals which possess different health benefits. This paper presents an overview of the most recent studies done on the matter. It intends to provide an in-depth understanding of the biological activities and medicinal uses of active constituents existing in C. aurantium. Every plant part is first discussed separately with regards to its content in active constituents. All extraction methods, their concepts and yields, used to recover these valuable molecules from their original plant matrix are thoroughly reported.
The increasing antimicrobial resistance requires continuous investigation of new antimicrobial agents preferably derived from natural sources. New powerful antibacterial agents can be produced by ...simply combining oils that are known for their antibacterial activities. In this study, apricot seed oil (ASO), date seed oil (DSO), grape seed oil (GSO), and black seed oil (BSO) alone and in binary mixtures were assessed. Fatty acid profiles of individual oils and oil mixtures showed linoleic acid, oleic acid, palmitic acid, stearic acid, and linolenic acid contents. Linoleic acid was the most abundant fatty acid in all samples except for ASO, where oleic acid was the dominant one. GSO showed the highest total phenolic content while ASO showed the lowest one. Antibacterial screening was performed against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus. Results showed antibacterial activity in all oils against tested strains except for ASO against S. aureus. Highest antibacterial activity recorded was for ASO against P. mirabilis. ASO-GSO mixture (AG) was the best mixture where it showed synergistic interactions against all strains except P. aeruginosa. In conclusion, seed oil mixtures are likely to show promising antibacterial activities against specific strains.
The effects of aqueous extraction of bioactive compounds from pomegranate peels using conventional extraction (CE) and extraction assisted by infrared irradiation (IR), ultrasound (US), pulsed ...electric fields (PEF), and high-voltage electrical discharges (HVED) have been compared. For the extractions assisted by US, PEF and HVED, the saturation in extraction was observed approximately at the same specific energy input in the order of W ≈ 90–100 kJ/kg. HVED assisted extraction enhanced the recovery of polyphenols by ≈3 and ≈1.3 times as compared to US and PEF assisted extractions, respectively. Scanning electron microscopy (SEM) data evidenced that the highest yield of total polyphenols after the HVED treatment can reflect the presence of a strong damage of the microstructure of pomegranate skins. The obtained data on inhibition of growth of A. flavus and biosynthesis of aflatoxin B1 were explained accounting for the presence of different synergetic effects of phenolic compounds on inhibition of different bioactivities. All the studied extracts (0.2 mg/mL) demonstrated the higher inhibition efficiency for S. aureus (up to ≈80%) as compared to E. coli (up to ≈33%). PEF selectively extracted and enhanced the recovery of ellagic acid (≈740 μg/g DM), whereas HVED (≈345 μg/g DM) intensified gallic acid extraction compared to US, IR, HVED and WB.
•HVED enhances the recovery of polyphenols as compared to US and PEF•HVED induces a strong damage of pomegranate skins•PEF recovers less polyphenols than HVED, but is more selective•HVED extracts inhibit the growth of A. flavus and the biosynthesis of aflatoxin B1•All extracts demonstrate higher inhibition for S. aureus as compared to E. coli
While world energy demand has certainly decreased with the beginning of the COVID-19 pandemic in 2020, the need has been significantly on the rise since 2021, all as the world’s fossil fuel resources ...are depleting; it is widely accepted that these resources emit greenhouse gases (GHG), which are the leading cause for the climate crisis. The main contributors to global warming are manufacturing, energy, and agriculture. The agricultural sector is composed of diversified and potential mobilizable sources of waste which can become an attractive alternative to fossil fuels for energy production, and thus sequester and use carbon. Therefore, a paradigm shift towards more sustainable energy alternatives, efficient waste management, and new technologies is necessary. One good solution is the energetic valorization of lignocellulosic biomass (LCB) which can also originate from agricultural wastes. The biomass consists of cellulose, hemicellulose, and lignin, which are sources of fermentable sugars that can be used for bioethanol production. However, the recovery of sugars requires the pretreatment of LCB before enzymatic hydrolysis, due to its inaccessible molecular structure. Different pretreatment technologies, including acid and alkaline pretreatments for selected biomasses (such as hemp, rice straw, corn straw, sugarcane bagasse, and wheat straw) are discussed and compared. Therefore, this review highlights the potential of agricultural waste as a renewable resource for energy production.
Orange peels are a biomass rich in carbohydrates and polyphenols and characterized by their low lignin content. This work focuses on finding the best combination between physical and biological ...treatments to enhance the extraction of fermentable sugars and polyphenols. High voltage electrical discharges (HVED) (0 to 900 kJ/kg) or enzymatic hydrolysis with Viscozyme® L (12 FBGU/g) were applied on fresh or defatted orange peels for the extraction of polyphenols and fermentable sugars. An HVED energy input of 222 kJ/kg was optimal for the extraction of reducing sugars (19 g/100 g DM) and polyphenols (0.7 g/100 g DM). However, enzymatic hydrolysis allowed a higher extraction of reducing sugars (50 g/100 g DM). HVED were then applied prior or simultaneously to enzymatic hydrolysis to maximize the extraction of biomolecules from orange peels. Thus, the results clearly showed that the HVED pretreatment of orange peels is efficient to enhance the accessibility of cellulosic biomass to enzymes. HVED (222 kJ/kg) prior to enzymatic hydrolysis (12 FBGU/g), was the most effective combination of these two processes to get an intensive extraction of biomolecules from orange peels.
•Polyphenols and fermentable sugars were extracted from orange peels.•HVED and enzymatic hydrolysis were applied on fresh and defatted orange peels.•A combination of the two treatments was realized to intensify the extraction.•HVED prior to enzymatic hydrolysis was the optimal combination.
This study aims to evaluate the impact of a nonconventional pretreatment technique “infrareds free solvent” on the intensification of polyphenols extraction from orange peels. Orange peels were ...pretreated with infrared heating using a ceramic infrared transmitter from 5 to 25 min at 50 °C. After the addition of the solvent on the pretreated peels, ultrasound treatment was applied on the mixture using an ultrasound generator connected to a titanium ultrasound probe, from 5 to 30 min, at 50 °C. Results showed that the application of ultrasounds on untreated peels enhanced the extraction of polyphenols by 62.5% compared to the conventional solid–liquid extraction. Twenty minutes of infrared pretreatment improved the extraction of polyphenols by 47% with solid–liquid extraction, and 112% with ultrasounds after 30 min compared to solid–liquid extraction from untreated peels. Different combinations of infrared pretreatment and ultrasound assisted extraction were then applied on orange peels. The most advantageous combination in terms of energy consumption and polyphenols extraction has been found for a 20 min infrared pretreatment time and 5 min ultrasound assisted extraction of polyphenols.
Practical Application
Orange peels are valuable sources of natural antioxidants such as polyphenols. Ultrasound‐assisted extraction can improve the extraction of polyphenols compared to conventional solid–liquid extraction. To intensify the extraction process, infrared heating can be used as a simple, low cost, and energy saving method. The combined effect of “infrareds free solvent” and ultrasounds allowed the extraction of the highest yields of polyphenols with a high antiradical capacity and a low energy consumption in comparison to conventional extraction.
PDF
