Emerging Green Techniques for the Extraction of Antioxidants from Agri-Food By-Products as Promising Ingredients for the Food Industry

Valorization of Sour Cherry Kernels: Extraction of Polyphenols Using Natural Deep Eutectic Solvents (NADESs)

The objective of this research was to optimize the natural deep eutectic solvent (NADES) extraction process from sour cherry kernels (Prunus cerasus L.). For polyphenol isolation, conventional solid-liquid extraction was employed using different concentrations of ethanol (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 96%), as well as the innovative NADES extraction technique. In the initial phase of the research, a screening of 10 different NADESs was conducted, while extraction was carried out under constant parameters (50 °C, 1:20 w/w, 60 min). NADES 4, composed of lactic acid and glucose in a molar ratio of 5:1, exhibited the highest efficiency in the polyphenol isolation. In the subsequent phase of the research, response surface methodology (RSM) was utilized to optimize the extraction process. Three independent variables, namely temperature, extraction time, and solid-liquid (S/L) ratio, were examined at three different levels. The extracted samples were analyzed for total phenol (TP) and antioxidant activity using the DPPH, ABTS, and FRAP assays. ANOVA and descriptive statistics (R2 and CV) were performed to fit the applied model. According to RSM, the optimal extraction conditions were determined as follows: temperature of 70 °C, extraction time of 161 min, and S/L ratio of 1:25 w/w.

Green Method Comparison and Optimization of Anthocyanin Recovery from "Sangiovese" Grape Pomace: A Critical Evaluation of the Design of Experiments Approach

Grape pomace is the main by-product obtained from wine production that is still enriched in bioactive compounds. Within a framework of waste/by-product reuse through a sustainable approach, various green methods were utilized in this work to recover anthocyanins from the pomace resulting from "Sangiovese" grape vinification. Ultrasound- and Microwave-Assisted Extractions (UAE and MAE) were coupled with the use of green solvents, such as acidified water, an ethanol/water mixture, and Natural Deep Eutectic Solvents (NaDES), and their efficacy was compared with that of a conventional method based on a methanol/acidified water mixture. The Total Anthocyanin Index ranged from 36.9 to 75.2 mg/g DW for UAE, and from 54.4 to 99.6 mg/g DW for MAE, while resulting in 47.1 mg/g DW for conventional extraction. A Design of Experiments (DoE) approach was applied to MAE, the most efficient technique. Temperature, time, and the solid-to-liquid ratio were set as X variables, while malvidin-3-O-glucoside content and antioxidant activity were used as response variables, measured by High-Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The correlation between temperature and time and the antioxidant activity of the extract was positive, while it was found to be negative when considering malvidin-3-O-glucoside concentration as a response variable. Thus, the optimal conditions in temperature, time and solid-to-liquid ratio were different depending on the chosen variable. The results underline the importance of selecting an accurate response when using the response surface methodology approach.

Green Extraction and Valorization of By-Products from Food Processing

Agro-industrial valorization has been a hot topic recently since it leads to resource conservation and is economically and environmentally valuable [...].

Enhancing Cutin Extraction Efficiency from Industrially Derived Tomato Processing Residues by High-Pressure Homogenization

This study primarily aimed to enhance the extraction of cutin from industrial tomato peel residues. Initially, the conventional extraction process was optimized using response surface methodology (RSM). Subsequently, high-pressure homogenization (HPH) was introduced to improve extraction efficiency and sustainability. The optimization process focused on determining the optimal conditions for conventional extraction via chemical hydrolysis, including temperature (100-130 °C), time (15-120 min), and NaOH concentration (1-3%). The optimized conditions, determined as 130 °C, 120 min, and 3% NaOH solution, yielded a maximum cutin extraction of 32.5%. Furthermore, the results indicated that applying HPH pre-treatment to tomato peels before alkaline hydrolysis significantly increased the cutin extraction yield, reaching 46.1%. This represents an approximately 42% increase compared to the conventional process. Importantly, HPH pre-treatment enabled cutin extraction under milder conditions using a 2% NaOH solution, reducing NaOH usage by 33%, while still achieving a substantial cutin yield of 45.6%. FT-IR analysis confirmed that cutin obtained via both conventional and HPH-assisted extraction exhibited similar chemical structures, indicating that the main chemical groups and structure of cutin remained unaltered by HPH treatment. Furthermore, cutin extracts from both conventional and HPH-assisted extraction demonstrated thermal stability up to approximately 200 °C, with less than 5% weight loss according to TGA analysis. These findings underscore the potential of HPH technology to significantly enhance cutin extraction yield from tomato peel residues while utilizing milder chemical hydrolysis conditions, thereby promoting a more sustainable and efficient cutin extraction process.

Statistical Tools to Optimize the Recovery of Bioactive Compounds from Marine Byproducts

Techniques for extracting important bioactive molecules from seafood byproducts, viz., bones, heads, skin, frames, fins, shells, guts, and viscera, are receiving emphasis due to the need for better valorization. Employing green extraction technologies for efficient and quality production of these bioactive molecules is also strictly required. Hence, understanding the extraction process parameters to effectively design an applicable optimization strategy could enable these improvements. In this review, statistical optimization strategies applied for the extraction process parameters of obtaining bioactive molecules from seafood byproducts are focused upon. The type of experimental designs and techniques applied to criticize and validate the effects of independent variables on the extraction output are addressed. Dominant parameters studied were the enzyme/substrate ratio, pH, time, temperature, and power of extraction instruments. The yield of bioactive compounds, including long-chain polyunsaturated fatty acids, amino acids, peptides, enzymes, gelatine, collagen, chitin, vitamins, polyphenolic constituents, carotenoids, etc., were the most studied responses. Efficiency and/or economic and quality considerations and their selected optimization strategies that favor the production of potential bioactive molecules were also reviewed.

Trends in extracting Agro-byproducts' phenolics using non-thermal technologies and their combinative effect: Mechanisms, potentials, drawbacks, and safety evaluation

The agro-food industries generate significant waste with adverse effects. However, these byproducts are rich in polyphenols with diverse bioactivities. Innovative non-thermal extraction (NTE) technologies (Naviglio extractor®, cold plasma (CP), high hydrostatic pressure (HHP), pulse-electric field (PEF), ultrasound-assisted extraction (UAE), etc.) and their combinative effect (integrated UAE + HPPE, integrated PEF + enzyme-assisted extraction, etc.) could improve polyphenolic extraction. Hence, this article comprehensively reviewed the mechanisms, applications, drawbacks, and safety assessment of emerging NTE technologies and their combinative effects in the last 5 years, emphasizing their efficacy in improving agro-byproduct polyphenols' extraction. According to the review, incorporating cutting-edge NTE might promote the extraction ofmore phenolic extractfrom agro-byproducts due to numerous benefits,such as increased extractability,preserved thermo-sensitive phenolics, and low energy consumption. The next five years should investigate combined novel NTE technologies as they increase extractability. Besides, more research must be done on extracting free and bound phenolics, phenolic acids, flavonoids, and lignans from agro by-products. Finally, the safety of the extraction technology on the polyphenolic extract needs a lot of studies (in vivo and in vitro), and their mechanisms need to be explored.

The Antioxidant and Neuroprotective Potential of Leaves and Inflorescences Extracts of Selected Hemp Varieties Obtained with scCO2

Cannabis sativa, a versatile plant with numerous varieties, holds promising potential for a wide range of biological activity. As raw materials for research, we chose leaves and inflorescences of hemp varieties such as Białobrzeskie, Henola, and Tygra, which are cultivated mainly for their fibers or seeds. The choice of extraction is a key step in obtaining the selected compositions of active compounds from plant material. Bearing in mind the lipophilic nature of cannabinoids, we performed supercritical carbon dioxide (scCO2) extraction at 50 °C under 2000 (a) and 6000 PSI (b). The cannabinoid contents were determined with the use of the HPLC-DAD method. The antioxidant capabilities were assessed through a series of procedures, including the DPPH, ABTS, CUPRAC, and FRAP methods. The capacity to inhibit enzymes that play a role in the progression of neurodegenerative diseases, such as acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase was also studied. The dominant cannabinoids in the extracts were cannabidiol (CBD) and cannabidiolic acid (CBDA). The highest concentration of eight cannabinoids was detected in the Tygra inflorescences extract (b). The most notable antioxidant properties were provided by the Tygra inflorescences extract (b). Nonetheless, it was the Henola inflorescences extract (b) that demonstrated the most efficient inhibition of AChE and BChE, and tyrosinase was inhibited the most significantly by the Białobrzeskie inflorescences extract (b). Multidimensional comparative analysis enrolled all assays and revealed that the Henola inflorescences extract (b) showed the most substantial neuroprotective potential.

Secondary Metabolites Generated from Saussurea lappa and Ligusticum sinensis Essential Oils by Microwave-Assisted Hydrodistillation: in Silico Molecular Docking and in Vitro Antibacterial Efficacy

In the current study, both the essential oil composition and biological activity of Saussurea lappa and Ligusticum sinensis were investigated by means of microwave-assisted hydrodistillation (MAHD) and characterized by Gas chromatography/mass spectrometry (GC/MS), whereas the antimicrobial efficiency of MAHD essential oils was examined against four pathogens: Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Candida albicans responsible for microbial infections. The goal was to spot synergy and a favorable method that gives essential oils to possibly use as alternatives to common antimicrobial agents for the treatment of bacterial infections using a microdilution assay. S. lappa's 21 compounds were characterized by MAHD extraction. Sesquiterpene lactones (39.7 % MAHD) represented the major components, followed by sesquiterpene dialdehyde (25.50 % MAHD), while L. sinensis's 14 compounds were identified by MAHD extraction. Tetrahydroisobenzofurans (72.94 % MAHD) was the predominant compound class. S. lappa essential oil collection showed the strongest antimicrobial activity with MIC values of 16 μg/ml against all pathogens tested, while L. sinensis showed strong antibacterial activity and moderate antifungal activity with MIC values of 32 μg/ml and 500 μg/ml, respectively. The principal components of both oils, (velleral, eremanthin and neocnidilide), were docked into the bacterial histidine kinase (HK) and the fungal heat shock protein 90 (Hsp90).

Sea Bass Side Streams Extracts Obtained by Pulsed Electric Fields: Nutritional Characterization and Effect on SH-SY5Y Cells

Fish side streams are an environmental and economic problem. In this work, pulsed electric fields (PEF) extraction was optimized and used as a new method for their valorization. Sea bass head, skin, viscera, and backbone were used. PEF technology (123-300 kJ/kg, 1-3 kV/cm) improved the extraction of proteins and antioxidant compounds from head and skin, but was not successful for viscera. SDS-PAGE showed that the protein molecular weight distribution was affected by the extraction process, revealing differences between the control and PEF extraction conditions. In addition, the extraction of macro-minerals and micro-minerals were also evaluated. The effect of PEF differed according to the matrix and the mineral studied. Heavy metals were also taken into account, studying the presence of As, Cd, Hg, and Pb in the extracts. PEF pre-treatment reduced the presence of As in skin, viscera, and backbone, ranging from 18.25 to 28.48% according to the matrix evaluated. The analysis of potential antioxidant bioactive peptides showed that the treatment of the sample directly influenced their variety. Additionally, the extracts obtained from the head were found to increase cell viability when tested on SH-SY5Y cells. In conclusion, PEF extraction can be a useful tool for the valorization of fish side streams.

Phytobioactive compounds as therapeutic agents for human diseases: A review

Phytobioactive compounds are plant secondary metabolites and bioactive compounds abundantly present in medicinal plants and have remarkable therapeutic potential. Oxidative stress and antibiotic resistance are major causes of present-day ailments such as diabetes, atherosclerosis, cardiovascular disorders, cancer, and inflammation. The data for this review were collected from Google Scholar, PubMed, Directory of Open Access Journals (DOAJ), and Science Direct by using keywords: "Medicinal plants, Phytobioactive compounds, Polyphenols, Alkaloids, Carotenoids etc." Several studies have reported the pharmacological and therapeutic potential of the phytobioactives. Polyphenols, alkaloids, terpenes, and polysaccharides isolated from medicinal plants showed remarkable antioxidant, anticancer, cytotoxic, anti-inflammatory, cardioprotective, hepatoprotective, immunomodulatory, neuroprotective, and antidiabetic activities. This literature review was planned to provide comprehensive insight into the biopharmacological and therapeutic potential of phytobioactive compounds. The techniques used for the extraction and isolation of phytobioactive compounds, and bioassays required for their biological activities such as antioxidant, antimicrobial, anti-inflammatory, and cytotoxic activities, have been discussed. Characterization techniques for the structural elucidation of phytobioactive compounds such as HPLC, TLC, FTIR, GC-MS/MS, and NMR have also been discussed. This review concludes that phytobioactive compounds may be used as potential alternative to synthetic compounds as therapeutic agents for the treatment of various diseases.

Food-Waste Valorisation: Synergistic Effects of Enabling Technologies and Eutectic Solvents on the Recovery of Bioactives from Violet Potato Peels

The recovery of valuable bioactive compounds from the main underutilised by-products of the food industry is one of the greatest challenges to be addressed in circular economy. Potato peels are the largest waste generated during potato processing. However, they could be a potential source of valuable bioactive compounds, such as polyphenols, that can be reused as natural antioxidants. Currently, environmentally benign enabling technologies and new types of non-toxic organic solvents for the extraction of bioactive compounds may dramatically improve the sustainability of these processes. This paper focuses on the potential inherent in the valorisation of violet potato peels (VPPs) by recovering antioxidants using natural deep eutectic solvents (NaDES) under ultrasound (US)- and microwave (MW)-assisted extraction. Both the enabling technologies provided performances that were superior to those of conventional extractions in terms of antioxidant activity determined by the DPPH· (2,2-diphenyl-1-picrylhydrazyl) assay. In particular, the most promising approach using NaDES is proven to be the acoustic cavitation with a Trolox eq. of 1874.0 mmolTE/gExtr (40 °C, 500 W, 30 min), vs. the 510.1 mmolTE/gExtr of hydroalcoholic extraction (80 °C, 4 h). The shelf-life of both hydroalcoholic and NaDES-VPPs extracts have been assessed over a period of 24 months, and found that NaDES granted a 5.6-fold shelf-life extension. Finally, the antiproliferative activity of both hydroalcoholic and NaDES-VPPs extracts was evaluated in vitro using the MTS assay on human tumour Caco-2 cells and normal human keratinocyte cells (HaCaT). In particular, NaDES-VPPs extracts exhibited a significantly more pronounced antiproliferative activity compared to the ethanolic extracts without a noteworthy difference between effects on the two cell lines.

Effect of ultra-high pressure pretreatment on the phenolic profiles, antioxidative activity and cytoprotective capacity of different phenolic fractions from Que Zui tea

This study aims to explore whether ultra-high pressure (UHP) pre-treatment strengthened the bioaccessibility and bioactivities of the free (QF), esterified (QE) and insoluble-bound phenolics (QIB) from Que Zui tea (QT). The results revealed that the extraction yields, the total phenolic (TPC) and total flavonoid contents (TFC) of three phenolic fractions from QT were markedly increased after ultra-high pressure (UHP) processing (p < 0.05). A total of 19 and 20 compounds were characterized and quantified in non- and UHP-treated QT, respectively, including the content of 6'-O-caffeoylarbutin (11775.68 and 13248.87 μg/g of dry extract) was highest in QF, the content of caffeic acid was highest in QE (2131.58 and 7362.99 μg/g of dry extract) and QIB (9151.89 and 10930.82 μg/g of dry extract). QF, QE and QIB from QT after UHP processing had better antioxidant, ROS scavenging, and anti-apoptosis effects. The possible mechanism of cytoprotective effect was related to Keap1-Nrf2 pathway.

Approaches to determine pesticides in marine bivalves

Due to agricultural runoff, pesticides end up in aquatic ecosystems and some accumulate in marine bivalves. As filter feeders, bivalves can accumulate high concentrations of chemicals in their tissue representing a potential risk to the health of human and aquatic ecosystems. So far, most of the studies dealing with pesticide contamination in marine bivalves, for example, in the French Atlantic and English Channel coasts, have focused on the old generation of pesticides. Only a few investigated the newly emerging pesticides partly due to methodological challenges. A better understanding of the most sensitive and reliable methods is thus essential for accurately determining a wide variety of environmentally relevant pesticides in marine bivalves. The review highlighted the use of more environmentally friendly and efficient materials such as sorbents and the "quick easy cheap effective rugged safe" extraction procedure to extract pesticides from bivalve matrices, as they appeared to be the most efficient while being the safest. Moreover, this method combined with the high-resolution mass spectrometry (MS) technique offers promising perspectives by highlighting a wide range of pesticides including those that are not usually sought. Finally, recent developments in the field of ultra-high-performance liquid chromatography coupled to MS, such as two-dimensional chromatography and ion mobility spectrometry, will improve the analysis of pesticides in complex matrices.

Impact of Ultrasonication on African Oil Bean (Pentaclethra macrophylla Benth) Protein Extraction and Properties

African oil bean (Pentaclethra macrophylla Benth) is an underutilised edible oil seed that could represent a sustainable protein source. In this study, the impact of ultrasonication on the extraction efficiency and properties of protein from African oil bean (AOB) seeds was evaluated. The increase in the duration of extraction favoured the extraction of AOB proteins. This was observed by an increase in extraction yield from 24% to 42% (w/w) when the extraction time was increased from 15 min to 60 min. Desirable properties were observed in extracted AOB proteins; the amino acid profile of protein isolates revealed higher ratios of hydrophobic to hydrophilic amino acids compared to those of the defatted seeds, suggesting alterations in their functional properties. This was also supported by the higher proportion of hydrophobic amino acids and high surface hydrophobicity index value (3813) in AOB protein isolates. The foaming capacity of AOB proteins was above 200%, with an average foaming stability of 92%. The results indicate that AOB protein isolates can be considered promising food ingredients and could help stimulate the growth of the food industry in tropical Sub-Saharan regions where AOB seeds thrive.

Pulsed electric fields-assisted extraction of valuable compounds from red grape pomace: Process optimization using response surface methodology

Background

The application of Pulsed electric fields as a mild and easily scalable electrotechnology represents an effective approach to selectively intensify the extractability of bioactive compounds from grape pomace, one of the most abundant residues generated during the winemaking process.

Objective

This study addressed the optimization of the pulsed electric fields (PEF)-assisted extraction to enhance the extraction yields of bioactive compounds from red grape pomace using response surface methodology (RSM).

Methods

The cell disintegration index (Z p ) was identified as response variable to determine the optimal PEF processing conditions in terms of field strength (E = 0.5-5 kV/cm) and energy input (WT = 1-20 kJ/kg). For the solid-liquid extraction (SLE) process the effects of temperature (20-50°C), time (30-300min), and solvent concentration (0-50% ethanol in water) on total phenolic content (TPC), flavonoid content (FC), total anthocyanin content (TAC), tannin content (TC), and antioxidant activity (FRAP) of the extracts from untreated and PEF-treated plant tissues were assessed. The phenolic composition of the obtained extracts was determined via HPLC-PDA.

Results

Results demonstrated that the application of PEF at the optimal processing conditions (E = 4.6 kV/cm, WT = 20 kJ/kg) significantly enhanced the permeabilization degree of cell membrane of grape pomace tissues, thus intensifying the subsequent extractability of TPC (15%), FC (60%), TAC (23%), TC (42%), and FRAP values (31%) concerning the control extraction. HPLC-PDA analyses showed that, regardless of the application of PEF, the most abundant phenolic compounds were epicatechin, p-coumaric acid, and peonidin 3-O-glucoside, and no degradation of the specific compounds occurred upon PEF application.

Conclusion

The optimization of the PEF-assisted extraction process allowed to significantly enhance the extraction yields of high-value-added compounds from red grape pomace, supporting further investigations of this process at a larger scale.

Biopolymer- and Lipid-Based Carriers for the Delivery of Plant-Based Ingredients

Natural ingredients are gaining increasing attention from manufacturers following consumers’ concerns about the excessive use of synthetic ingredients. However, the use of natural extracts or molecules to achieve desirable qualities throughout the shelf life of foodstuff and, upon consumption, in the relevant biological environment is severely limited by their poor performance, especially with respect to solubility, stability against environmental conditions during product manufacturing, storage, and bioavailability upon consumption. Nanoencapsulation can be seen as an attractive approach with which to overcome these challenges. Among the different nanoencapsulation systems, lipids and biopolymer-based nanocarriers have emerged as the most effective ones because of their intrinsic low toxicity following their formulation with biocompatible and biodegradable materials. The present review aims to provide a survey of the recent advances in nanoscale carriers, formulated with biopolymers or lipids, for the encapsulation of natural compounds and plant extracts.

Persistence and remote sensing of agri-food wastes in the environment: Current state and perspectives

Food demand is expected to increase globally by 60-110% from 2005 to 2050 due to diet shifts and population growth. This growth in food demand leads to the generation of enormous agri-food wastes (AFWs), which could be classified into pre-consumption and post-consumption. The AFW represents economic losses for all stakeholders along food supply chains, including consumers. It is reported that the direct financial, social, and environmental costs of food waste are 1, 0.9, and 0.7 trillion USD/year, respectively. Diverse conventional AFW management approaches are employed at the different life cycle levels (entre supply chain). The review indicates that inadequate transportation, erroneous packaging, improper storage, losses during processing, contamination, issues with handling, and expiry dates are the main reason for the generation of AFWs in the supply chain. Further, various variables such as cultural, societal, personal, and behavioral factors contribute to the AFW generation. The selection of a specific valorization technology is based on multiple physicochemical and biological parameters. Furthermore, other factors like heterogeneity of the AFWs, preferable energy carriers, by-products management, cost, end-usage applications, and environmental legislative and disposal processes also play a crucial role in adopting suitable technology. Valorization of AFW could significantly impact both economy and the environment. AFWs have been widely investigated for the development of engineered added-value biomaterials and renewable energy production. Considering this, this study has been carried out to highlight the significance of AFW cost, aggregation, quantification, and membrane-based strategies for its management. The study also explored the satellite remote sensing data for Spatio-temporal monitoring, mapping, optimization, and management of AFW management. Along with this, the study also explained the most recent strategies for AFW valorization and outlined the detailed policy recommendation along with opportunities and challenges. The review suggested that AFW should be managed using a triple-bottom-line strategy (economic, social, and environmental sustainability).

A subcritical water extract of soil grown Zingiber officinale Roscoe: Comparative analysis of antioxidant and anti-inflammatory effects and evaluation of bioactive metabolites

Introduction: Ginger (Zingiber officinale Roscoe) can scavenge free radicals, which cause oxidative damage and inflamm-ageing. This study aimed to evaluate the antioxidant and anti-inflammatory effects of soil ginger's sub-critical water extracts (SWE) on different ages of Sprague Dawley (SD) rats. The antioxidant properties and yield of SWE of soil- and soilless-grown ginger (soil ginger and soilless ginger will be used throughout the passage) were compared and evaluated. Methods: Three (young), nine (adult), and twenty-one (old) months old SD rats were subjected to oral gavage treatments with either distilled water or the SWE of soil ginger at a concentration of 200 mg/kg body weight (BW) for three months. Results: Soil ginger was found to yield 46% more extract than soilless ginger. While [6]-shogaol was more prevalent in soilless ginger, and [6]-gingerol concentration was higher in soil ginger (p < 0.05). Interestingly, soil ginger exhibited higher antioxidant activities than soilless ginger by using 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay. With ginger treatment, a reduced levels of tumour necrosis factor-α (TNF-α) and C-reactive protein (CRP) but not interleukin-6 (IL-6) were observed in young rats. In all ages of SD rats, ginger treatment boosted catalase activity while lowering malondialdehyde (MDA). Reduction of urine 15-isoprostane F_2t in young rats, creatine kinase-MM (CK-MM) in adult and old rats and lipid peroxidation (LPO) in young and adult rats were also observed. Discussion: The findings confirmed that the SWE of both soil and soilless grown ginger possessed antioxidant activities. Soil ginger produced a higher yield of extracts with a more prominent antioxidant activity. The SWE of soil ginger treatment on the different ages of SD rats ameliorates oxidative stress and inflammation responses. This could serve as the basis for developing a nutraceutical that can be used as a therapeutic intervention for ageing-related diseases.

Potential of phenolic compounds from pomegranate (Punica granatum L.) by-product with significant antioxidant and therapeutic effects: A narrative review

The wealth of epidemiological evidence in the scientific world underscores the possibility that a plant-based diet can reduce the prevalence of common diseases such as diabetes, cardiovascular disease, cancer, and stroke. The therapeutic effects of plant sources are partly explained by phenolic secondary metabolites or polyphenolic compounds. Therefore, polyphenolic compounds, which are widely distributed in plants, are of great interest for the development of effective specific drugs with antioxidant and anti-inflammatory effects. Moreover, polyphenol compounds have no harmful effects due to their natural biocompatibility and safety. Numerous studies have highlighted the potential of some industrial food wastes from plant material processing, including apple peels and mashed potatoes, grape skins, tomato and carrot peels, pomegranate peels and seeds, and many others. These byproducts are considered low-cost sources of natural biological compounds, including antioxidants, which have beneficial effects on human health. The polyphenol complex of pomegranate peel (Punica granatum L.), which makes up half of the pomegranate fruit, has more pronounced antioxidant and anti-inflammatory properties than other parts. And the most important active components of pomegranate peel, which are found only in this plant, are punicalagin, followed by ellagic acid and gallic acid. It is known that these polyphenolic compounds of pomegranate peel have the most pronounced therapeutic effect. Several studies have shown the protective effect of ellagic acid, punicalagin, against oxidative stress damage caused by free radicals. The potential of pomegranate peel as an antioxidant and therapeutic component in various biological systems is high, according to scientific sources. However, despite extensive research in recent years, a review of sources has shown that there is insufficient evidence to support the therapeutic effects of polyphenolic compounds from pomegranate peels. The role of pomegranate peel polyphenolic compounds, including flavonoids, as antioxidants in various biological systems also requires further research. Of particular importance are the mechanisms by which antioxidants influence the cellular response against oxidative stress. The purpose of this review was to report our current knowledge of plant polyphenolic compounds and their classification, and to evaluate the potential of phenolic compounds from pomegranate peels with significant antioxidant and therapeutic effects.

Sustainable Extraction Methods Affect Metabolomics and Oxidative Stability of Myrtle Seed Oils Obtained from Myrtle Liqueur By-Products: An Electron Paramagnetic Resonance and Mass Spectrometry Approach

Myrtle liqueur production generates high amounts of by-products that can be employed for the extraction of bioactive compounds. Bio-based, non-toxic and biodegradable solvents (ethyl acetate and 2-methyltetrahydrofuran), and a mechanical extraction were applied to myrtle seeds, by-products of the liqueur production, to extract oils rich in phenolic compounds. The oils obtained were characterized for yield, peroxide value (PV), lipid composition, and total phenolic concentration (TPC). The phenolic profile of the oils, determined by LC-MS, the antioxidant activity, and the oxidative stability were also analyzed. A validated UHPLC-ESI-QTRAP-MS/MS analytical method in multiple reaction monitoring (MRM) mode was applied to quantify myricetin and its main derivatives in myrtle oils. The results pointed out clear differences among extraction methods on myricetin concentration. The oxidative stability of myrtle oils was studied with electron paramagnetic resonance (EPR) spectroscopy highlighting the effect of the extraction method on the oxidation status of the oils and the role of phenolic compounds in the evolution of radical species over time. A principal component analysis applied to LC-MS data highlighted strong differences among phenolic profiles of the oils and highlighted the role of myricetin in the oxidative stability of myrtle oils. Myrtle oil, obtained from the by-products of myrtle liqueur processing industry, extracted with sustainable and green methods might have potential application in food or cosmetic industries.

Current Challenges in the Sustainable Valorisation of Agri-Food Wastes: A Review

In the upcoming years, the world will face societal challenges arising, in particular, from the impact of climate change and the inefficient use of natural resources, in addition to an exponential growth of the world population, which according to the United Nations (UN) estimations will be 9.8 billion in 2050. This increasing trend requires optimized management of natural resources with the use of value-added waste and a significant reduction in food loss and food waste. Moreover, the recent pandemic situation, COVID-19, has contributed indisputably. Along with the agri-food supply chain, several amounts of waste or by-products are generated. In most cases, these biomass wastes cause serious environmental concerns and high costs to enterprises. The valorisation of the agri-food loss and food industry wastes emerged as a useful strategy to produce certain value-added compounds with several potential applications, namely in the food, health, pharmaceutical, cosmetic, and environmental fields. Therefore, in this review, some of the crucial sustainable challenges with impacts on the valorisation of agri-food loss/wastes and by-products are discussed and identified, in addition to several opportunities, trends and innovations. Potential applications and usages of the most important compounds found in food loss/waste will be highlighted, with a focus on the food industry, pharmaceutical industry, and the environment.

Effects of In Vitro Digestion on the Antioxidant Activity of Three Phenolic Extracts from Olive Mill Wastewaters

The aim of this study was to assess the impact of in vitro digestion on the antioxidant activity of three extracts rich in phenols (two purified organic extracts (A20, A21) and one powdered extract stabilized with maltodextrins (SP)) obtained from olive mill wastewaters (OMWW). The content and composition of phenols and antioxidant activity was determined before and after in vitro digestion. The phenol content of the A20 and A21 samples were higher (>75%) than that of the SP sample before in vitro digestion. After the entire in vitro digestion, 89.3, 76.9, and 50% loss of phenols was found in A20, A21 and SP, respectively. ABTS•+ and ORAC values decreased during in vitro digestion of A20 and A21 samples, while they remained almost constant in SP. IC50 increased during digestion of A20 and A21, evidencing a loss of antioxidant capacity after the intestinal phase; an opposite IC50 trend was noted in SP, confirming the protective role of maltodextrins. For these reasons, SP represents a promising formulation to be used in the food field.

Integrated Technology for Cereal Bran Valorization: Perspectives for a Sustainable Industrial Approach

Current research focuses on improving the bioaccessibility of functional components bound to cereal bran cell walls. The main bioactive components in cereal bran that have major biological activities include phenolic acids, biopeptides, dietary fiber, and novel carbohydrates. Because of the bound form in which these bioactive compounds exist in the bran matrix, their bioaccessibility is limited. This paper aims to comprehensively analyze the functionality of an integrated technology comprising pretreatment techniques applied to bran substrate followed by fermentation bioprocesses to improve the bioaccessibility and bioavailability of the functional components. The integrated technology of specific physical, chemical, and biological pretreatments coupled with fermentation strategies applied to cereal bran previously-pretreated substrate provide a theoretical basis for the high-value utilization of cereal bran and the development of related functional foods and drugs.

Optimization of bioactives extraction from grape marc via a medium scale ambient temperature system and stability study

A scalable procedure with minimum energy requirements, MSAT (Medium Scale Ambient Temperature), in combination with solvents generally recognized as safe (GRAS), has been optimized to obtain polyphenolic extracts from white grape (Vitis vinifera) marc. The solvents considered were propylene glycol (Pg), ethanol (Et), and ethyl lactate (Lc), as well as their respective hydro-organic mixtures. In a first approach, the operating parameters were optimized through a response surface matrix: extraction solvent volume (range 10-150 mL), marc mass (range 20-200 g) and marc/dispersant mass ratio (range 0.5-2 g⋅g^-1), using the total polyphenol content (TPC) and the antioxidant activity (AA) of the extracts as response parameters. The highest TPC (5,918 mgGAE⋅L^-1) and AA (44 mmolTE⋅L^-1) values were obtained using 200 g marc and 100 mL solvent. Regarding the type of solvent, a better response was reached with Lc > Et > Pg > H₂O obtaining a polyphenol concentration of 252 mg⋅L^-1 for the hydro-organic isovolumetric ratio of ethyl lactate. In addition, the stability of the extracts was studied for 62 days. The effect of factors such as temperature, light exposure, and oxidative reactivity was evaluated. The bioactivity indices showed no changes with the storage conditions of the extracts in the first month of analysis, after which 75% of the antioxidant activity as the concentration of the polyphenolic profile (204 mg⋅L^-1) remains. The absence of reactive oxygen and the cooling of the extract (4°C) were the most determining factors (p < 0.05) in modulating the stability of the total polyphenolic profile.

Utilizing Nutritional and Polyphenolic Compounds in Underutilized Plant Seeds for Health Application

Plants represent a significant part of the human diet. Humans have utilized every part of plants for survival, and seeds are no exception. Seeds offer high protein, unsaturated fats, fibre, essential vitamins, and minerals for various food applications. They are also a promising reservoir of bioactive compounds, where various phytochemicals, such as polyphenolic compounds, capable of maintaining and improving well-being, are present in abundant quantities. Plants from Malvaceae and Cannabaceae families are known for their fibre-rich stems that benefit humankind by serving numerous purposes. For many centuries they have been exploited extensively for various commercial and industrial uses. Their seeds, which are often regarded as a by-product of fibre processing, have been scientifically discovered to have an essential role in combating hypercholesterolemia, diabetes, cancer, and oxidative stress. Maximizing the use of these agricultural wastes can be a promising approach to creating a more sustainable world, in accordance with the concept of Sustainable Development Goals (SDGs).

Variability in Biological Activities of Satureja montana Subsp. montana and Subsp. variegata Based on Different Extraction Methods

Winter savory (Satureja montana L.) is a well-known spice and medicinal plant with a wide range of activities and applications. Two subspecies of S. montana, subsp. montana and subsp. variegata, were used for the preparation of seven different extracts: steam distillation (essential oil (EO) and hydrolate (HY)), subcritical water (SWE), ultrasound-assisted (UAE-MeOH and UAE-H₂O), and microwave-assisted (MAE-MeOH and MAE-H₂O) extraction. The obtained EOs, HYs, and extracts were used for an in vitro evaluation of the antioxidant activity (DPPH, ABTS, reducing power, and superoxide anion methods) and in vitro antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella Typhimurium, Saccharomyces cerevisiae, and Candida albicans. The antimicrobial screening was conducted using disk-diffusion assessment, minimal inhibitory concentration, time–kill kinetics modeling, and pharmacodynamic study of the biocide effect. The total phenolic content (TPC) was highest in EO, followed by SWE, MAE, and UAE, and the lowest was in HY. The highest antimicrobial activity shows EO and SWE for both varieties, while different UAE and MAE extracts have not exhibited antimicrobial activity. The natural antimicrobials in the S. montana extract samples obtained by green extraction methods, indicated the possibility of ecologically and economically better solutions for future in vivo application of the selected plant subspecies.

Impact of Kefiran Exopolysaccharide Extraction on Its Applicability for Tissue Engineering and Regenerative Medicine

Kefiran is an exopolysaccharide produced by the microflora of kefir grains used to produce the fermented milk beverage kefir. The health-promoting and physicochemical properties of kefiran led to its exploration for a range of applications, mainly in the food industry and biomedical fields. Aiming to explore its potential for tissue engineering and regenerative medicine (TERM) applications, the kefiran biopolymer obtained through three different extraction methodologies was fully characterized and compared. High-quality kefiran polysaccharides were recovered with suitable yield through different extraction protocols. The methods consisted of heating the kefir grains prior to recovering kefiran by centrifugation and differed mainly in the precipitation steps included before lyophilization. Then, kefiran scaffolds were successfully produced from each extract by cryogelation and freeze-drying. In all extracts, it was possible to identify the molecular structure of the kefiran polysaccharide through ¹H-NMR and FTIR spectra. The kefiran from extraction 1 showed the highest molecular weight (~3000 kDa) and the best rheological properties, showing a pseudoplastic behavior; its scaffold presented the highest value of porosity (93.2% ± 2), and wall thickness (85.8 µm ± 16.3). All extracts showed thermal stability, good injectability and desirable viscoelastic properties; the developed scaffolds demonstrated mechanical stability, elastic behavior, and pore size comprised between 98–94 µm. Additionally, all kefiran products proved to be non-cytotoxic over L929 cells. The interesting structural, physicochemical, and biological properties showed by the kefiran extracts and cryogels revealed their biomedical potential and suitability for TERM applications.

Cereal Waste Valorization through Conventional and Current Extraction Techniques-An Up-to-Date Overview

Nowadays, in the European Union more than 100 million tons of food are wasted, meanwhile, millions of people are starving. Food waste represents a serious and ever-growing issue which has gained researchers’ attention due to its economic, environmental, social, and ethical implications. The Sustainable Development Goal has as its main objective the reduction of food waste through several approaches such as the re-use of agro-industrial by-products and their exploitation through complete valorization of their bioactive compounds. The extraction of the bioactive compounds through conventional methods has been used for a long time, whilst the increasing demand and evolution for using more sustainable extraction techniques has led to the development of new, ecologically friendly, and high-efficiency technologies. Enzymatic and ultrasound-assisted extractions, microwave-assisted extraction, membrane fractionation, and pressure-based extraction techniques (supercritical fluid extraction, subcritical water extraction, and steam explosion) are the main debated green technologies in the present paper. This review aims to provide a critical and comprehensive overview of the well-known conventional extraction methods and the advanced novel treatments and extraction techniques applied to release the bioactive compounds from cereal waste and by-products.

Towards the Preparation of a Hydrogel from Lyophilisates of the Aloe arborescens Aqueous Extract

Aloe gel is a medicinal raw material with proven pharmacological activity. The health-promoting properties of other species of Aloe upon topical application prompted us to develop a formulation for the topical application of A. arborescence species. As a result of the gel preparation from the aqueous lyophilized extracts of three-year-old leaves of A. arborescence, no changes in the composition of the content of aloins A and aloenin A were found. The potential to neutralize free radicals was tested using DPPH and CUPRAC techniques, which confirmed the anti-radical activity of the lyophilisate. Screening of the inhibition of enzymes, the hyperactivity of which is associated with adverse changes in the skin of a pro-inflammatory nature, was performed. Importantly, using the PAMPA SKIN model, the possibility of the penetration of selected extract compounds (aloin A and aloenin A) through the skin was proven. Then, two formulations were prepared based on sodium alginate and hydroxypropyl methylcellulose (HPMC) and the hydrogels were characterized (rheological analysis, drug release profiles, permeability, and stability studies). HPMC-based hydrogel was the one with a targeted release of active substances and greater stability. Aloe arborescens hydrogel matrices seem to be a promising treatment strategy for inflammatory surface damage based on “green technology” at the stage of extract preparation and development of the drug form for topical application.

Extraction of Polyphenolic Antioxidants from Red Grape Pomace and Olive Leaves: Process Optimization Using a Tailor-Made Tertiary Deep Eutectic Solvent

In the framework of introducing green strategies for food processing, the industrial orientation has shifted towards the replacement of conventional petroleum-based solvents with alternative eco-friendly ones. On this basis, the objective of this study was to synthesize a novel, tertiary, food-grade deep eutectic solvent, composed of glycerol, citric acid, and L-proline (GL-CA-Pro), and to test it as a solvent for the extraction of polyphenols from agri-food waste biomass. After an initial screening on various common residual materials (apple peels, lemon peels, orange peels, red grape pomace, olive leaves), evidence emerged that indicated GL-CA-Pro was more effective than other DESs commonly used for polyphenol extraction. Furthermore, extracts from red grape pomace (RGP) and olive leaves (OLL) were shown to contain higher level of total polyphenols and increased antioxidant activity. Process optimization for those two materials with the response surface methodology revealed that the major difference pertained to the extraction time. In addition, for both materials, GL-CA-Pro was shown to provide higher total polyphenol yields (53.25 and 42.48 mg gallic acid equivalents per g of dry mass, respectively) compared to water and 60% aqueous ethanol. However, the chromatographic analyses for OLL suggested aqueous ethanol was a more suitable solvent for some principal polyphenolic constituents. The RGP extract produced with GL-CA-Pro exhibited significantly stronger antioxidant effects compared to the aqueous and hydroethanolic extracts, but the outcome for the OLL extracts was diversified. It was concluded that GL-CA-Pro is a very efficient solvent for RGP polyphenols, but its efficiency regarding OLL was comparable to that of aqueous ethanol.

Ultrasound-Assisted Extraction of Natural Pigments From Food Processing By-Products: A Review

Ultrasound is an emerging technology, which has been highly explored in the food area to improve processes and products. When ultrasound is applied to a product with solid or fluid characteristics, the passage of acoustic waves and acoustic cavitation generates different mechanisms responsible for modifications in the original matrix of the sample. These effects of ultrasound can also be used to take advantage of by-products, for example by extracting compounds of interest, including natural pigments. Natural pigments or colorants are being highly demanded by different industries not only for color purposes but also due to their healthy properties, the greater demands in regulations and new consumer preferences. This review presents an updated critical analysis of the application of ultrasound-assisted extraction (UAE) to obtain natural pigments from food processing by-products. Initially, the ultrasound effects and mechanisms that improve the extraction of natural pigments in a fluid medium, as well as the factors that influence the extraction and the energy consumption of UAE are analyzed and described. Subsequently, the UAE application to obtain pigments belonging to the groups of carotenoids, chlorophyll, anthocyanins and betalains is evaluated. These sections detail the processing conditions, positive and negative effects, as well as possible applications of the extracted pigments. This review presents relevant information that may be useful to expand and explore new applications of ultrasound technology as well as promote the revaluation of by-products to obtain pigments that can be used in food, pharmaceutical or cosmetic industries.

Polyphenols Recovery from Thymus serpyllum Industrial Waste Using Microwave-Assisted Extraction-Comparative RSM and ANN Approach for Process Optimization

The aim of this study was to valorize Thymus serpyllum L. herbal dust, the particular fraction distinguished as industrial waste from filter-tea production. This work demonstrated comparable analysis considering model fitting, influence analysis and optimization of microwave-assisted extraction (MAE) of bioactive compounds from the aforementioned herbal dust using face-centered central composite experimental design within the response surface methodology (RSM), as well as artificial neural networks (ANN). In order to increase yield and amount of compounds of interest and minimize solvent, time and energy consumption, the ethanol concentration (45, 60 and 75%), extraction time (5, 12.5 and 20 min), liquid–solid ratio (10, 20 and 30 mL/g) and irradiation power (400, 600 and 800 W) were used as independent variables. Total extraction yield (Y), total phenols yield (TP), as well as antioxidant activity parameters obtained by DPPH and ABTS assays, were selected as responses. It could be concluded that the MAE technique is an efficient approach for the extraction of biologically active compounds from T. serpyllum herbal dust, which represents a high-value source of natural antioxidants with great potential for further use in various forms within different branches of industry.

Lipid Extracts Obtained by Supercritical Fluid Extraction and Their Application in Meat Products

Supercritical fluid extraction (SFE) has been recognized as the green and clean technique without any negative impact on the environment. Although this technique has shown high selectivity towards lipophilic bioactive compounds, very few case studies on the application of these extracts in final products and different food matrices were observed. Considering the recent developments in food science and the increasing application of supercritical extracts in meat products in the last decade (2012–2022), the aim of this manuscript was to provide a systematic review of the lipid extracts and bioactives successfully obtained by supercritical fluid extraction and their application in meat products as antioxidant and/or antimicrobial agents. Lipophilic bioactives from natural resources were explained in the first step, which was followed by the fundamentals of supercritical fluid extraction and application on recovery of these bioactives. Finally, the application of natural extracts and bioactives obtained by this technique as functional additives in meat and meat products were thoroughly discussed in order to review the state-of-the-art techniques and set the challenges for further studies.

Phytocompounds as an Alternative Antimicrobial Approach in Aquaculture

Despite culturing the fastest-growing animal in animal husbandry, fish farmers are often adversely economically affected by pathogenic disease outbreaks across the world. Although there are available solutions such as the application of antibiotics to mitigate this phenomenon, the excessive and injudicious use of antibiotics has brought with it major concerns to the community at large, mainly due to the rapid development of resistant bacteria. At present, the use of natural compounds such as phytocompounds that can be an alternative to antibiotics is being explored to address the issue of antimicrobial resistance (AMR). These phytocompounds are bioactive agents that can be found in many species of plants and hold much potential. In this review, we will discuss phytocompounds extracted from plants that have been evidenced to contain antimicrobial, antifungal, antiviral and antiparasitic activities. Further, it has also been found that compounds such as terpenes, phenolics, saponins and alkaloids can be beneficial to the aquaculture industry when applied. This review will focus mainly on compounds that have been identified between 2000 and 2021. It is hoped this review will shed light on promising phytocompounds that can potentially and effectively mitigate AMR.

Pulsed Electric Field-Assisted Extraction of Aroma and Bioactive Compounds From Aromatic Plants and Food By-Products

In this work, the effect of pulsed electric field (PEF) pre-treatment on the extractability in green solvents (i. e., ethanol–water mixture and propylene glycol) of target aroma and bioactive compounds, such as vanillin from vanilla pods, theobromine and caffeine from cocoa bean shells, linalool from vermouth mixture, and limonene from orange peels, was investigated. The effectiveness of PEF as a cell disintegration technique in a wide range of field strength (1–5 kV/cm) and energy input (1–40 kJ/kg) was confirmed using impedance measurements, and results were used to define the optimal PEF conditions for the pre-treatment of each plant tissue before the subsequent solid–liquid extraction process. The extracted compounds from untreated and PEF-treated samples were analyzed via GC-MS and HPLC-PDA analysis. Results revealed that the maximum cell disintegration index was detected for cocoa bean shells and vanilla pods (Z_p = 0.82), followed by vermouth mixture (Z_p = 0.77), and orange peels (Z_p = 0.55). As a result, PEF pre-treatment significantly enhanced the extraction yield of the target compounds in both solvents, but especially in ethanolic extracts of vanillin (+14%), theobromine (+25%), caffeine (+34%), linalool (+114%), and limonene (+33%), as compared with untreated samples. Moreover, GC-MS and HPLC-PDA analyses revealed no evidence of degradation of individual compounds due to PEF application. The results obtained in this work suggest that the application of PEF treatment before solid–liquid extraction with green solvents could represent a sustainable approach for the recovery of clean labels and natural compounds from aromatic plants and food by-products.

Citrus Peel Extracts for Industrial-Scale Production of Bio-Based Active Food Packaging

The thermal stability of four different commercial citrus peel extracts was tested and improved by an encapsulation process with β-cyclodextrins in a spray-dryer. All extracts after the encapsulation process maintained a good antioxidant capacity, with an apparent loss in total phenolic compounds of around 20–25%. In addition, all samples showed good antimicrobial activity (MIC 5–0.625 mg/mL) against Staphylococcus aureus, which was maintained after the encapsulation process (MIC 5–1.25 mg/mL). Based on the antioxidant and antimicrobial activity results, the best-encapsulated citrus extract was selected for incorporation into a polylactic acid/polyhydroxy butyrate (PLA/PHB) film. The latter was then produced on an industrial scale by cast extrusion and was found to be suitable for food contact as it showed overall migration values in different food simulants lower than the legislative limit of 10 mg of non-volatile substances per 1 dm² of surface area. The UHPLC-HRMS analysis, performed to evaluate the migration of the active compounds, revealed about 13.41% release in food simulant A and 11.02% in food simulant B. Antimicrobial analysis conducted directly on the film showed a growth inhibition activity towards Escherichia coli and Staphylococcus aureus equal to 30 and 60%, respectively.

Improved Oxidative Stability and Sensory Quality of Beef Hamburgers Enriched with a Phenolic Extract from Olive Vegetation Water

This study aims at evaluating the effect of a phenol-rich extract obtained from the concentration and purification of olive mill wastewaters (added at a ratio of 87.5 and 175 mg of phenols/kg meat) on the stability and sensory quality of beef hamburgers packed under modified atmosphere and stored under alternating exposure to fluorescent light at 4 ± 2 °C for 9 days. The hamburgers were sampled at different times (0, 6, and 9 days) and grilled at 200 °C. After 9 days, more than 56% of the added phenols in the raw burgers and more than 20% the grilled ones were retained. The results show that both concentrations of phenolic extract proved to effectively reduce primary and secondary lipid oxidation, as well as cholesterol oxidation products (COPs), during the shelf-life of raw hamburgers. Peroxide value, thiobarbituric acid reactive substances, and total COPs were up to 1.4-, 4.5-, and 8.8-fold lower in phenol-enriched raw hamburgers, respectively, than in the control samples; a similar trend was noted also in phenol-enriched cooked hamburgers (1.3-, 5.7-, and 4-fold lower). The sensory analysis also confirmed the effectiveness of the addition of phenolic extract, resulting in a positive effect on the red color intensity (raw product) and thus reducing browning during storage.