Natural deep eutectic solvents pretreatment as an aid for pectin extraction from apple pomace

Investigating the synergistic effects of apple vinegar and deep eutectic solvent as natural antibiotics: an experimental and COSMO-RS analysis

The present investigation examines the antimicrobial and antifungal characteristics of natural deep eutectic solvents (NADES) and apple vinegar in relation to a diverse array of bacterial and fungal strains. The clinical bacterial strains, including gram-negative and gram-positive, and the fungal pathogen Candida albicans, were subjected to solid medium diffusion to determine the inhibitory effects of these compounds. The results show that NADES has superior antimicrobial and antifungal action compared to apple vinegar. The observed inhibitory zones for apple vinegar and NADES varied in length from 16.5 to 24.2 and 16 to 52.5 mm, respectively. The results obtained indicate that no synergy is observed for this mixture (50% AV + 50% NADES). The range of values for bactericidal concentrations (MBC) and minimal inhibitory concentrations (MIC) was 0.0125 to 0.2 and 0.0125 to 0.4 µl/ml, respectively. Antibacterial and antifungal chemicals may be found in apple vinegar and NADES, with NADES offering environmentally safe substitutes for traditional antibiotics. Additional investigation is suggested to refine these compounds for a wide range of bacteria, which could create antimicrobial solutions that are both highly effective and specifically targeted, thereby offering extensive potential in medicine and the environment.

Structural and functional characteristics of pectins from three cultivars of apple (Malus pumila Mill.) pomaces

This study aimed to investigate the chemical composition, structural properties, and biological properties of pectin polysaccharides (AP-FS, AP-QG, and AP-HG) isolated from different varieties of apple pomace. Based on the methylation and nuclear magnetic resonance analyses, the structure of AP-FS was determined to be composed of an α-1,4-linked homogalacturonan backbone that exhibited high levels of O-6 methylation. All pectins exhibit potent inhibitory activity against human colon cancer and human liver cancer cells, along with immunostimulatory effects. Among them, AP-FS exhibited the highest activity level. Finally, we further investigated the underlying mechanism behind the effect of AP-FS on RAW 264.7 cells using proteomics analysis. Our findings revealed that AP-FS triggers RAW 264.7 macrophage activation via NOD-like receptor (NLR), NF-κB, and mitogen-activated protein kinase (MAPK) signaling pathways. Therefore, our research contributes to a better understanding of the structure-function relationship among apple pectins, and AP-FS has the potential to be applied to dietary supplements targeting immunomodulation.

Extraction of Lentinus Edodes Polysaccharides with Ultrasound Enhanced with Deep Eutectic Solvent and Their Structural Characterization and Antioxidant Activity

Ultrasound extraction (UE) enhanced with deep eutectic solvent (DES) was used to extract Lentinus edodes polysaccharides. Box-Behnken design (BBD) was applied to investigate the influences of water content (10-90 %), solid-liquid solvent (1 : 10-1 : 50 g/mL), time (4-12 min), temperature (40-80 °C) and ultrasonic power (100-500 W) on the yield of Lentinus edodes polysaccharides. The optimal extraction conditions were ultrasonic power of 300 W, extraction time of 8 min, water content of 80 %, a solid-liquid ratio of 1 : 30 g/mL and a temperature of 60 °C, respectively. The highest extraction yield of Lentinus edodes polysaccharide was 10.17 % under optimal conditions. The results of FT-IR, SEM, and monosaccharide composition confirmed that the extracts possessed the characteristics of polysaccharides. In addition, the polysaccharides obtained with the UE enhanced with DES method exhibited higher antioxidant activities than the polysaccharides extracted with the UE method and HWE method. This extraction method can further expand the production efficiency and structural diversity of Lentinus edodes polysaccharides and meet the supply and demand relationship. It can be foreseen that this method can be applied to the extraction of more active substances.

Simultaneously efficient dissolution and structural modification of chrysanthemum pectin: Targeting at proliferation of Bacteroides

Pectic polysaccharide is a bioactive ingredient in Chrysanthemum morifolium Ramat. 'Hangbaiju' (CMH), but the high proportion of HG domain limited its use as a prebiotic. In this study, hot water, cellulase-assisted, medium-temperature alkali, and deep eutectic solvent extraction strategies were firstly used to extract pectin from CMH (CMHP). CMHP obtained by cellulase-assisted extraction had high purity and strong ability to promote the proliferation of Bacteroides and mixed probiotics. However, 4 extraction strategies led to general high proportion of HG domain in CMHPs. To further enhance the dissolution and prebiotic potential of CMHP, pectinase was used alone and combined with cellulase. The key factor for the optimal extraction was enzymolysis by cellulase and pectinase in a mass ratio of 3:1 at 1 % (w/w) dosage. The optimal CMHP had high yield (15.15 %), high content of total sugar, and Bacteroides proliferative activity superior to inulin, which was probably due to the cooperation of complex enzyme on the destruction of cell wall and pectin structural modification for raised RG-I domain (80.30 %) with relatively high degree of branching and moderate HG domain. This study provided a green strategy for extraction of RG-I enriched prebiotic pectin from plants.

Deep eutectic solvents: Preparation, properties, and food applications

Deep Eutectic Solvents (DESs) emerge as innovative 21st-century solvents, supplanting traditional ones like ethanol and n-hexane. Renowned for their non-toxic, biodegradable, and water-miscible nature with reduced volatility, DESs are mostly synthesized through heating and stirring method. Physicochemical properties such as polarity, viscosity, density and surface tension of DESs influenced their application. This review paper gives the overview of application of eco-benign DESs in fruits, vegetables, cereals, pulses, spices, herbs, plantation crops, oil seed crops, medicinal and aromatic plants, seaweed, and milk for the extraction of bioactive compounds. Also, it gives insight of determination of pesticides, insecticides, hazardous and toxic compounds, removal of heavy metals, detection of illegal milk additive, purification of antibiotics and preparation of packaging film. Methodologies for separating bioactive compounds from DESs extracts are systematically examined. Further, safety regulations of DESs are briefly discussed and reviewed literature reveals prevalent utilization of DES-based bioactive compound rich extracts in cosmetics, indicating untapped potential of their application in the food industry.

Deep eutectic solvents pretreatment enhances methane production from anaerobic digestion of waste activated sludge: Effectiveness evaluation and mechanism elucidation

Anaerobic digestion (AD) is a prevalent waste activated sludge (WAS) treatment, and optimizing methane production is a core focus of AD. Two DESs were developed in this study and significantly increased methane production, including choline chloride-urea (ChCl-Urea) 390% and chloride-ethylene glycol (ChCl-EG) 540%. Results showed that ChCl-Urea mainly disrupted extracellular polymeric substances (EPS) structures, aiding in initial sludge solubilization during pretreatment. ChCl-EG, instead, induced sludge self-driven organic solubilization and enhanced hydrolysis and acidification processes during AD process. Based on the extent to which the two DESs promoted AD for methane production, the AD process can be divided into stage Ⅰ and stage Ⅱ. In stage Ⅰ, ChCl-EG promoted methanogenesis more significantly, microbiological analysis showed both DESs enriched aceticlastic methanogens-Methanosarcina. Notably, ChCl-Urea particularly influenced polysaccharide-related metabolism, whereas ChCl-EG targeted protein-related metabolism. In stage Ⅱ, ChCl-Urea was more dominant than ChCl-EG, ChCl-Urea bolstered metabolism and ChCl-EG promoted genetic information processing in this stage. In essence, this study investigated the microbial mechanism of DES-enhanced sludge methanogenesis and provided a reference for future research.

Gut microbiota modulation, prebiotic and bioactive characteristics of date pomace polysaccharides extracted by microwave-assisted deep eutectic solvent

This study investigated the characteristics of polysaccharides from date pomace using microwave-assisted deep eutectic solvents. The impact on the gut microbiota and probiotics growth was examined in vitro. The study also examined its antioxidant properties, ability to inhibit enzymes linked to diabetes and high blood pressure, impact on cell growth, and physical properties. The isolated MPS had an average molecular weight of 8073.38 kDa and contained mannose, galacturonic acid, galactose, glucose, and fructose in specific proportions. At a concentration of 1000 mg/L, MPS showed strong antioxidant activity, with significant scavenging rates in various tests such as DPPH (57.0 ± 1.05 %) and ABTS (66.4 ± 2.48 %). MPS displayed 77 %, 80 %, and 43 % inhibition for α-amylase, α-glucosidase, and ACE-inhibition, respectively. MPS displayed significant antiproliferative effects, achieving 100 % and 99 % inhibition against Caco-2 and MCF-7 cells at 2500 mg/L, respectively. MPS showed broad-spectrum antibacterial properties against both Gram-positive and Gram-negative foodborne bacteria. Gemmiger formicilis, Blautia species, Collinsella aerofaciens, and Bifidobacterium longum showed strong positive correlations, suggesting increased SCFA production. Network analysis indicated species correlations, with 86 % showing negative correlations with Escherichia and Enterococcus saccharolyticus. MPS was abundant in Firmicutes, Actinobacteria, and Proteobacteria phyla. Date pomace could serve as a dietary fiber source, promoting better health.

Efficient and Selective Extraction of Rhamnogalacturonan-I-Enriched Pectic Polysaccharides from Tartary Buckwheat Leaves Using Deep-Eutectic-Solvent-Based Techniques

Tartary buckwheat green leaves are considered to be among the most important by-products in the buckwheat industry. Although Tartary buckwheat green leaves are abundant in pectic polysaccharides, their potential applications in the food industry are quite scarce. Therefore, to promote their potential applications as functional or fortified food ingredients, both deep-eutectic-solvent-assisted extraction (DESE) and high-pressure-assisted deep eutectic solvent extraction (HPDEE) were used to efficiently and selectively extract pectic polysaccharides from Tartary buckwheat green leaves (TBP). The results revealed that both the DESE and HPDEE techniques not only improved the extraction efficiency of TBP but also regulated its structural properties and beneficial effects. The primary chemical structures of TBP extracted using different methods were stable overall, mainly consisting of homogalacturonan and rhamnogalacturonan-I (RG-I) pectic regions. However, both the DESE and HPDEE methods could selectively extract RG-I-enriched TBP, and the proportion of the RG-I pectic region in TBP obviously improved. Additionally, both the DESE and HPDEE methods could improve the antioxidant and anti-glycosylation effects of TBP by increasing its proportion of free uronic acids and content of bound polyphenolics and reducing its molecular weight. Moreover, both the DESE and HPDEE methods could partially intensify the immunostimulatory effect of TBP by increasing its proportion of the RG-I pectic region. These findings suggest that DES-based extraction techniques, especially the HPDEE method, can be promising techniques for the efficient and selective extraction of RG-I-enriched TBP.

An eco-friendly extraction method to obtain pectin from passion fruit rinds (Passiflora edulis sp.) using subcritical water and pressurized natural deep eutectic solvents

This work evaluated the efficiency of Subcritical Water Extraction (SWE) and Pressurized Natural Deep Eutectic Solvents (P-NaDESs) under different temperatures (100, 120, 140 and 160 °C) in obtaining pectin from Passion Fruit Rinds (PFR) and its residual biomass (PFR - UAPLE), and compare the results with those of Conventional Extraction (CE). The highest pectin yields, 19.1 and 27.6 %, were achieved using P-NaDES (Citric Acid:Glucose:Water) at 120 °C for PFR and its PFR-UAPLE, respectively. Regarding the Degree of Esterification (DE), pectin obtained with SWE and CE had DE below 50 %, while with P-NaDES (Citric Acid: Glucose:Water), DE was above 50 %. Higher Molecular Weights (MW) (98 and 81 kDa) were obtained with SWE and P-NaDES from PFR compared to PFR-UAPLE and CE. Galacturonic acid was the most abundant (74 to 78 %) monosaccharide obtained by SWE. In terms of morphology, water extraction provided pectin with more uniform textures, whereas extraction with acidified mixtures led to more heterogeneous surfaces. Overall, comparing SWE and P-NaDES, the obtained pectins differed in terms of monomeric composition, MW and DE. These results indicate that pectins obtained by both methods can have different applications depending on their structural characteristics.

Extraction of pectins from renewable grapefruit (Citrus paradisi) peels using deep eutectic solvents and analysis of their structural and physicochemical properties

This study presents an innovative attempt to extract high-quality pectins from grapefruit (Citrus paradisi) peels by using deep eutectic solvents (DESs) as extraction agents. The maximum yield of betaine-citric acid (BC)-extracted pectin (BC-P) reached 36.47 % under the optimum process conditions: an L/S ratio of 25 mL/g, a pH of 2.0, and a temperature of 85 °C for 120 min. The yield of BC-P was significantly higher than HCl-extracted pectin (HCl-P, 8.76 %) under a pH of 2.0. In addition, the structural, physicochemical, and emulsifying properties of the purified pectins (BC-P and HCl-P) and commercial pectin (CP) were comparatively analyzed. Results showed that BC-P exhibited higher RG-I value, more arabinan side-chains, bigger Mw and Mn value than HCl-P. Moreover, the viscosity, G' and G'' of BC-P were significantly higher than those of HCl-P and CP. More importantly, BC-P demonstrated better emulsifying activity and stability compared to HCl-P and CP. When the concentration of BC-P was increased to 1.50 %, a stable emulsion containing a 50 % soybean oil fraction could be obtained. Our results confirmed that DESs can be considered as high-effective agents for pectin extraction. Pectins extracted from grapefruit peels can be as a promising natural emulsifiers that can be used in the food industry.

Exploring apple pectic polysaccharides: Extraction, characterization, and biological activities - A comprehensive review

Apple (Malus domestica) is a popular and ancient fruit of the Myrtaceae family. Apple fruit is well-known for its great nutritional and phytochemical content consisted of beneficial compounds such as polyphenols, polysaccharides, sterols, and organic acids. Polysaccharides extracted from different parts of the apple fruit, including the peel, pomace, or the whole fruit, have been extensively studied. Researchers have investigated the structural characteristics of these polysaccharides, such as molecular weight, type of monosaccharide unit, type of linkage and its position and arrangement. Besides this, functional properties and physicochemical and of apple polysaccharides have also been studied, along with the effects of extraction procedures, storage, and processing on cell wall polysaccharides. Various extraction techniques, including hot water extraction, enzymatic extraction, and solvent-assisted extraction, have been studied. From the findings, it was evident that apple polysaccharides are mainly composed of (1 → 3), (1 → 6): α-β-glycosidic linkage. Moreover, the apple polysaccharides were demonstrated to exhibit antioxidant, hepatoprotective, anti-cancer, hypoilipidemic, and enzyme inhibitory properties in vitro and in vivo. The potential applications of apple polysaccharides in the food, cosmetic, pharmaceutical, nutraceutical industries have also been explored in the present review. Overall, the research on apple polysaccharides highlights their significant potential as a source of biologically active compounds with various health benefits and practical applications.

An Acid-Free Alternative to Pectin Production from the Cell Walls of Olive Oil Waste and Different Fruits Using Choline Chloride

The pectin from the cell walls of olive waste (alperujo) and apple, orange and strawberry fruits was extracted using choline chloride (ChCl) and the yield and chemical and structural compositions were compared to pectin extracted using citric acid (CA) and ammonium oxalate/oxalic acid (AOOA). According to the results, the alperujo pectin extracted using ChCl from alcohol-insoluble residue (AIR) showed a higher yield (2.20-2.88% on the basis of dry weight of AIR) than using CA (0.65-1.22%) but lower than using AOOA (3.92-5.42%). For fruit pectin, the highest yield was obtained using CA (8.81-16%), followed by AOOA (5.4-6.63%), although for apple pectin, ChCl gave a similar yield (5.36%) to AOOA. The uronic acid contents in all ChCl pectins (45.9-70.6% dry basis AIR) were higher or similar to that of the other extracting agents (30.6-65.2%), although a lower level of neutral sugar side chains was detected, with a lower degree of branching and degree of methylation. The NMR and FT-IR spectroscopy of the pectin isolated using ChCl confirmed its slightly different structural composition with respect to CA and AOOA pectin. Therefore, depending on the source material and functionality, pectin isolated using ChCl could be an acid-free alternative to pectin production.

Valorization of coffee bean processing waste for the sustainable extraction of biologically active pectin

The dry method of coffee processing generates a significant amount of coffee husk, an agricultural waste for which currently there is a lack of profitable use, and their disposal constitutes a major environmental problem. Pectin was extracted from coffee husk using citric acid solution (pH 1.5) by microwave-assisted extraction method, followed by using ice-cold ethanol. The coffee husk pectin (CHP) with a yield of 40.2% was characterized using SEM, FT-IR, and XRD techniques. The CHP exhibited significant in-vitro antioxidant activity as measured by using 2,2-diphenyl-1-picrylhydrazyl; (IC50 value of 395.1 ± 0.42 μg/mL), ferrous reducing antioxidant capacity (A700 nm = 0.55 ± 0.08), 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging (42.02 ± 0.38%) and ascorbic acid auto-oxidation inhibition (92.01 ± 0.28%) assays. CHP demonstrated antibacterial activity against Escherichia coli and Bacillus cereus with an inhibition diameter of 20 ± 1.01 mm and 18 ± 0.84 mm, respectively. Interestingly, CHP showed a significant anti-inflammatory effect by negatively modulating the expressions of TNF-α and TGF- β in LPS-stimulated macrophage cell lines. Collectively, our findings suggest that the coffee husk is a potential source of commercial pectin, microwave-assisted extraction has a great potency on the commercial pectin extraction from the coffee husk and CHP demonstrates significant biological activity.

Natural deep eutectic solvents for Ultrasonic-Assisted extraction of nutritious date Sugar: Molecular Screening, Experimental, and prediction

The aim of this study is to develop an environmentally friendly and effective method for the extraction of nutritious date sugar using natural deep eutectic solvents (NADES) and ultrasound-assisted extraction (USAE). The careful design of a suitable NADES-USAE system was systematically supported by COSMO-RS screening, response surface method (RSM) and artificial neural network (ANN). Initially, 26 natural hydrogen bond donors (HBDs) were carefully screened for sugar affinity using COSMO-RS. The best performing HBDs were then used for the synthesis of 5 NADES using choline chloride (ChCl) as HBA. Among the synthesized NADES, the mixture of ChCl, citric acid (CA) and water (1:1:1 with 20 wt% water) resulted in the highest sugar yield of 78.30 ± 3.91 g/100 g, which is superior to conventional solvents such as water (29.92 ± 1.50 g/100 g). Further enhancements using RSM and ANN led to an even higher sugar recovery of 87.81 ± 2.61 g/100 g, at conditions of 30 °C, 45 min, and a solvent to DFP ratio of 40 mL/g. The method NADES-USAE was then compared with conventional hot water extraction (CHWE) (61.36 ± 3.06) and showed 43.1% higher sugar yield. The developed process not only improves the recovery of the nutritious date sugar but also preserves the heat-sensitive bioactive compounds in dates, making it an attractive alternative to CHWE for industrial utilization. Overall, this study shows a promising approach for the extraction of nutritive sugars from dates using environmentally friendly solvents and advanced technology. It also highlights the potential of this approach for valorizing underutilized fruits and preserving their bioactive compounds.

Exploring the effect of utilising organic acid solutions in ultrasound-assisted extraction of pectin from apple pomace, and its potential for biomedical purposes

Biomass resulting from food production represents valuable material to recover different biomolecules. In our study, we used apple pomace to obtain pectin, which is traditionally extracted using mineral acids. Our hypothesis consisted of carrying out extractions with organic acids, assisted by ultrasound, by varying processing parameters including time, temperature, and type of acid. The analytical determinations of galacturonic acid content, methoxylation and esterification degree, ζ-potential and extraction yield were used as pectin quality indicators. Pectins extracted using treatment conditions with better performance were assessed biologically in vitro for their potential to be used in biomedical applications. Overall, the extracted pectin presented a galacturonic acid content, methoxylation and esterification degree ranged from 19.7 to 67%, 26.8-41.4% and 58-65.2% respectively, and were negatively charged (-24.1 to -13.2 mV). It was found that factors of time and temperature greatly influenced the response variables excepting the esterification degree, while the acid type influenced the ζ-potential, methoxylation and esterification degrees. Additionally, it was seen that the longer extraction time (50 min) and higher temperature (50 °C) exhibited the better extraction yield (∼10.9%). Finally, the selected pectin showed high cytocompatibility up to 500 μg/mL of concentration when seeded with Neonatal Normal Human Dermal Fibroblasts.

Eco-friendly simultaneous extraction of pectins and phenolics from passion fruit (Passiflora edulis Sims) peel: Process optimization, physicochemical properties, and antioxidant activity

The objective of this study was to simultaneously extract passion fruit (Passiflora edulis) peel pectins and phenolics using deep eutectic solvents, to evaluate their physicochemical properties and antioxidant activity. By taking L-proline: citric acid (Pro-CA) as the optimal solvent, the effect of extraction parameters on the yields of extracted passion fruit peel pectins (PFPP) and total phenolic content (TPC) was. and the highest TPC (9.68 mg GAE/g DW) were attained under 90 °C, extraction solvent pH = 2, extraction time of 120 min and L/S ratio of 20 mL/g. In addition, Pro-CA-extracted pectins (Pro-CA-PFPP) and HCl-extracted pectins (HCl-PFPP) were subjected to high performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), thermogram analysis (TG/DTG) and rheological measurements. Results verified that the Mw and thermal stability of Pro-CA-PFPP were higher than those of HCl-PFPP. The PFPP solutions featured a non-Newtonian behavior, and compared with commercially pectin solution, PFPP solution exhibited a stronger antioxidant activity. Additionally, passion fruit peel extract (PFPE) exhibited stronger antioxidant effects than PFPP. The results of ultra-performance liquid chromatography hybrid triple quadrupole-linear ion trap mass spectrometry (UPLC-Qtrap-MS) and high performance liquid chromatography (HPLC) analysis showed that (-)-epigallocatechin, gallic acid, epicatechin, kaempferol-3-O-rutin and myricetin were the main phenolic compounds in PFPE and PFPP. Our results suggest that Pro-CA can be considered as an eco-friendly solvent for high-efficient extraction of high-value compounds from agricultural by-products.

Current progress in valorization of food processing waste and by-products for pectin extraction

Food processing waste and by-products such as peel of citrus fruit, melon, mango, pineapple, etc. and fruit pomace can be utilized for manufacturing of several high-value products. Valorization of these waste and by-products for extraction of pectin, can help offset growing environmental concerns, facilitate value-addition of by-products and their sustainable uses. Pectin has many applications in food industries such as gelling, thickening, stabilizing, and emulsifying agent, and as a dietary fibre. This review elaborates on various conventional and advanced, sustainable pectin extraction techniques, and paints a comparative picture between them considering extraction efficiency, quality, and functionality of the pectin. Conventional acid, alkali, and chelating agents-assisted extraction have been profusely used for pectin extraction, but advanced extraction technologies e.g., enzyme, microwave, supercritical water, ultrasonication, pulse electric field and high-pressure extraction are preferred due to less energy consumption, better quality product, higher yield, and minimal or no generation of harmful effluent.

Extraction of polyphenols associated with pectin from olive waste (alperujo) with choline chloride

The main by-product from olive oil extraction (alperujo) was extracted with hot water, citric acid, natural deep eutectic solvent (choline chloride: citric acid), and only choline chloride. The purified extracts were composed of macromolecular complexes constituting polyphenols associated with pectin. The extracts were structurally characterized by FT-IR and solid-NMR spectroscopy and an in vitro test revealed distinct antioxidant and antiproliferative activity, depending on the extracting agents. The choline chloride-extracted complex contained the highest amount of polyphenols among the examined agents, which exhibited a strong antioxidant activity and significant antiproliferative capacity. However, the complex extracted by hot water showed the highest antiproliferative capacity in vitro against the colon carcinoma Caco-2 cell line. In this finding, choline chloride could be used as a novel, green and promising alternative to the conventional extracting agent for the production of complexes that combine the antioxidant activity of phenolic compounds and the physiological effects of pectic polysaccharides.

High-performance arabinoglucuronoxylan-based biosurfactants for oily sludge separation

Arabinoglucuronoxylan (AGX), an important carbohydrate polymer in lignocellulosic biomass, contains many functional groups. It has excellent amphiphilic modification properties and has potential application in the separation of oily sludge. In this study, a simple strategy for producing high-performance AGX-based biosurfactants was studied and the raw AGX was extracted from bamboo by hydrothermal treatment. AGX-based biosurfactants with amphiphilic structure were produced by AGX and dodecanal succinic anhydride (DDSA) using rapid homogeneous esterification reactions in deep eutectic solvents (DES). This resulted in a significant reduction in the surface tension of the water from 72.32 to 29.76 mN·m^-1. These parameters are similar to those achieved using sodium dodecyl sulfate (SDS), a widely employed synthetic surfactant. Other physicochemical properties, including foamability, emulsification activity, stability, solubilization, and detergency were significantly improved compared to the unmodified AGX, demonstrate that AGX-based biosurfactants are promising detergents for oily sludge remediation and oil recovery. The results provide a new pathway for high value utilization of arabinoglucuronoxylan.

Upgrading the Functional Potential of Apple Pomace in Value-Added Ingredients with Probiotics

Emerging customized designs to upgrade the functional potential of freeze-dried apple pomace was used in this study, in order to transform the industrial by-products into ingredients containing probiotics, for a better and healthier food composition. The freeze-dried apple pomace was analyzed for free and bounded phenolic contents, highlighting a significant level of caffeic acid (4978.00 ± 900.00 mg/100 g dry matter (DM)), trans-cinnamic acid (2144.20 ± 37.60 mg/100 g DM) and quercetin 3-β-D-glucoside (236.60 ± 3.12 mg/100 g DM). The pectin extraction yield was approximatively 24%, with a degree of esterification of 37.68 ± 1.74%, and a methoxyl content of 5.58 ± 0.88%. The freeze-dried apple pomace was added in a different ratio as a supplement to cultural medium of Loigolactobacillus bifermentans MIUG BL 16, suggesting a significant prebiotic effect (p < 0.05) at concentration between 1% and 2%. The apple pomace was used to design three freeze-dried ingredients containing probiotic, with a high level of polyphenolic content (6.38 ± 0.14 mg gallic acid equivalents/g DM) and antioxidant activity (42.25 ± 4.58 mMol Trolox/g DM) for the powder containing apple pomace ethanolic extract. When inulin was used as a prebiotic adjuvant, the obtained powder showed a 6 log/g DM viable cell count. The ingredients were added to fermented vegetable soy milk-based products, allowing us to improve the polyphenolic content, antioxidant activity and viable cell counts. The approach designed in this study allowed us to obtain ingredients suitable to add value to food, whereas premises to align with the current circular economy premises, by reintegrating the industrial waste as sources of high added value compounds, are also provided.

Microwave-Assisted Deep Eutectic Solvent Extraction, Structural Characteristics, and Biological Functions of Polysaccharides from Sweet Tea (Lithocarpus litseifolius) Leaves

The leaf of sweet tea (Lithocarpus litseifolius) is widely used as an edible and medicinal plant in China, which is rich in bioactive polysaccharides. In order to explore and promote the application of sweet tea polysaccharides in the functional food industry, the microwave-assisted deep eutectic solvent extraction (MDAE) of polysaccharides from sweet tea leaves was optimized, and the structural properties and biological functions of sweet tea polysaccharides prepared by MDAE (P-DM) were investigated and compared with that of hot water extraction (P-W). The maximum yield (4.16% ± 0.09%, w/w) of P-DM was obtained under the optimal extraction conditions (extraction time of 11.0 min, extraction power of 576.0 W, water content in deep eutectic solvent of 21.0%, and liquid–solid ratio of 29.0 mL/g). Additionally, P-DM and P-W possessed similar constituent monosaccharides and glycosidic bonds, and the homogalacturonan (HG) and arabinogalactan (AG) might exist in both P-DM and P-W. Notably, the lower molecular weight, higher content of total uronic acids, and higher content of conjugated polyphenols were observed in P-DW compared to P-W, which might contribute to its much stronger in vitro antioxidant, anti-diabetic, antiglycation, and prebiotic effects. Besides, both P-DW and P-W exhibited remarkable in vitro immunostimulatory effects. The findings from the present study indicate that the MDAE has good potential to be used for efficient extraction of bioactive polysaccharides from sweet tea leaves and P-DM can be developed as functional food ingredients in the food industry.

Subcritical Water Enhanced with Deep Eutectic Solvent for Extracting Polysaccharides from Lentinus edodes and Their Antioxidant Activities

In the present study, subcritical water extraction (SWE) assisted with deep eutectic solvent (DES) is used to extract Lentinus edodes polysaccharides (LEP). In addition, the antioxidant activity of the polysaccharide samples was also investigated. Based on a single factor test and response surface test, the optimal extraction factors were a liquid–solid solvent of 40:1 mL/g, extraction temperature of 147.23 °C, water content of 39.76% and extraction time of 17.58 min. Under these extraction conditions, the yield of LEP was 6.26 ± 0.08%. Compared with the SWE and hot water extraction (HWE), it improved by 19.24% and 17.01%, respectively. In addition, the results of monosaccharide composition, molecular weight, FT-IR, UV and SEM confirmed that the extracts had the features of polysaccharides. Interestingly, the polysaccharides obtained with the SWE assisted with the DES procedure showed a higher DPPH scavenging activity, hydroxyl radical scavenging activity and hydrogen peroxide scavenging activity, which indicated that the polysaccharides with this method had a stronger antioxidant activity. These findings demonstrated that the SWE-assisted DES is a strong method to obtain polysaccharides from Lentinus edodes for food, biopharmaceutical and other industrial production.

A Comparative Assessment on the Recovery of Pectin and Phenolic Fractions from Aqueous and DES Extracts Obtained from Melon Peels

This work evaluates the purification of melon peel extracts obtained by two eco-friendly methods: autohydrolysis and sodium acetate/urea/water extraction (1:3:1.6), an alkaline deep eutectic solvent (DES). For that, sequential ethanol precipitation and resin adsorption/desorption stages were proposed for the separate recovery of the pectic and phenolic fractions. In order to screen the optimal purification conditions, in a first step, the effect of ethanol concentrations (from 70 to 85%) on the precipitation of pectic oligosaccharides was assayed. Subsequently, the influence of the selected resin (Amberlite XAD4, XAD16HP and XAD7HP), liquid/resin ratios, and desorption sequences (varying ethanol concentrations and pH) on the phenolic compounds was also studied. The highest pectin yields were achieved with 85% ethanol: 16.11 and 18.05 g pectin/100 g water-insoluble solids (WIS) for autohydrolysis and DES extracts, respectively. All pectins presented a galacturonic acid content of about 45%, while autohydrolysis pectin presented a higher amount of neutral sugar side chains. The presence of low methoxyl GalA and both linear and branched OGalA with DP from 2 to 20 was also confirmed by FTIR and HPAEC-PAD analysis, respectively. Concerning the phenolic fraction, the resin adsorption and desorption steps at the selected conditions (XAD4 resin, liquid/resin ratio of 2 mL/g, eluted with 50% ethanol thrice) resulted in 79.55 and 4.08 mg GAE/g non-volatile content (NVC) for autohydrolysis and DES extracts, respectively, with improved antioxidant capacity. Moreover, some phenolic acids (protocatechuic and ferulic acids) and flavonoids (orientin, vitexin and naringenin) were quantified in the extracts by HPLC–PDA-MS/MS.

The effect of sonication-synergistic natural deep eutectic solvents on extraction yield, structural and physicochemical properties of pectins extracted from mango peels

In this study, eco-friendly deep eutectic solvents (DESs) were used as extracting agents for the first time in the extraction of pectins from mango peel. Two novel green solvents including betaine-citric acid (Bet-CA) and choline chloride-malic acid (ChCl-MaA) were screened, and the extraction conditions were further optimized by full factor design experimental along with RSM. In addition, ultrasound treatment also had an influence on extraction yield, structural and physicochemical properties of extracted pectins. Two DES-extracted pectins had significantly higher yield, larger molecular weight and particles size than HCl-extracted pectin. High intensity ultrasound power enhanced the yield of low-ester pectins, but decreased the molecular weight and particles size of the pectins extracted. Monosaccharide compositions analysis showed that higher content of galacturonic acid (GalA) and larger HG region were observed in two DESs-extracted pectins. Fourier transform infrared spectra (FT-IR) of all pectins extracted were similar, with slight differences. Two DESs-extracted pectins exhibited higher DE values than HCl-extracted pectin. Thermal analysis and zeta potential results showed that HCl-extracted pectin had better stability than ChCl-MaA-extracted pectin. Additionally, HCl-extracted pectin had higher viscosity properties than two DESs-extracted pectins or commercial pectin (CP). Moreover, it was found that HCl-extracted pectin was in a colloid state, while two DESs-extracted pectins or CP were in a flow state. Ultrasound treatment significantly improved the yields of pectin/low-ester pectin. Additionally, ultrasound treatment remarkably decreased the viscosity and viscoelastic properties of the pectins extracted. The results were conducive to our understanding of the relationship between extraction conditions and physicochemical properties of the pectins extracted, which provides theoretical basis for the functional application of mango peel pectins in the food and pharmaceutical industry.

Analysis of Fatty Acids, Amino Acids and Volatile Profile of Apple By-Products by Gas Chromatography-Mass Spectrometry

Apple industrial by-products are a promising source of bioactive compounds with direct implications on human health. The main goal of the present work was to characterize the Jonathan and Golden Delicious by-products from their fatty acid, amino acid, and volatile aroma compounds’ point of view. GC-MS (gas chromatography-mass spectrometry) and ITEX/GC-MS methods were used for the by-products characterization. Linoleic and oleic were the main fatty acids identified in all samples, while palmitic and stearic acid were the representant of saturated ones. With respect to amino acids, from the essential group, isoleucine was the majority compound identified in JS (Jonathan skin) and GS (Golden skin) samples, lysine was the representant of JP (Jonathan pomace), and valine was mainly identified in GP (Golden pomace). A total number of 47 aroma volatile compounds were quantified in all samples, from which the esters groups ranged from 41.55–53.29%, aldehydes 29.75–43.99%, alcohols from 4.15 to 6.37%, ketones 4.14–5.72%, and the terpenes and terpenoids group reached values between 2.27% and 4.61%. Moreover, the by-products were valorized in biscuits manufacturing, highlighting their importance in enhancing the volatile aroma compounds, color, and sensorial analysis of the final baked goods.

Challenges and solutions of extracting value-added ingredients from fruit and vegetable by-products: a review

Every year, huge amounts of fruit and vegetable by-products in the food processing factories are produced. These by-products have great potential to be used for different targets especially the extraction of value-added ingredients. The target of this study is to review the challenges of extraction of value-added ingredients from fruit and vegetable by-products on the industrial scale and to describe current trends in solving these problems. In addition, some strategies such as multi-component extraction as well as application of fermentation before or after the extraction process, and production of biofuel, organic fertilizers, animal feeds, etc. on final residues after extraction of value-added ingredients are discussed in this review paper. In fact, simultaneous extraction of different value-added ingredients from fruit and vegetable by-products can increase the extraction efficiency and reduce the cost of value-added ingredients as well as the final volume of these by-products. After extraction of value-added ingredients, the residues can be used to produce biofuels, or they can be used to produce organic fertilizers, animal feeds, etc. Therefore, the application of several appropriate strategies to treat the fruit and vegetable by-products can increase their application, protect the environment, and improve the food economy.

Biopolymer poly-hydroxyalkanoates (PHA) production from apple industrial waste residues: A review

Apple pomace, the residue which is left out after processing of apple serves as a potential carbon source for the production of biopolymer, PHA (poly-hydroxyalkanoates). It is rich in carbohydrates, fibers and polyphenols. Utilization of these waste resources has dual societal benefit-waste management and conversion of waste to an eco-friendly biopolymer. This will lower the overall economics of the process. A major limitation for the commercialization of biopolymer in comparison with petroleum derived polymer is the high cost. This article gives an overview of valorization of apple pomace for the production of biopolymer, various strategies adopted, limitations as well as future perspectives.

Biomass Valorization Using Natural Deep Eutectic Solvents: What's New in France?

With the growing interest in more environmentally friendly solvents and processes, the introduction of Natural Deep Eutectic Solvents (NaDES) as low cost, non-toxic and biodegradable solvents represent a new opportunity for green and sustainable chemistry. Thanks to their remarkable advantages, NaDES are now arousing growing interest in many fields of research such as food, health, cosmetics and biofuels. Around the world, NaDES are seen as a promising alternative to commonly used petrochemical solvents. The objective of this review is to draw up a panorama of the existing skills on NaDES in French laboratories and industries for the valuation of natural products. This review therefore focuses on current applications, skills and perspectives, in order to analyze the place of French research in the use of NaDES for the valorization of biomass since 2015.

Deep Eutectic Solvent-Assisted Extraction, Partially Structural Characterization, and Bioactivities of Acidic Polysaccharides from Lotus Leaves

Lotus leaves are often discarded as byproducts in the lotus industry. Polysaccharides are regarded as one of the essentially bioactive components in lotus leaves. Therefore, in order to promote the application of lotus leaves in the functional food industry, the deep eutectic solvent (DES) assisted extraction of polysaccharides from lotus leaves (LLPs) was optimized, and structural and biological properties of LLPs extracted by DES and hot water were further investigated. At the optimal extraction conditions (water content of 61.0% in DES, extraction temperature of 92 °C, liquid-solid ratio of 31.0 mL/g and extraction time of 126 min), the maximum extraction yield (5.38%) was obtained. Furthermore, LLP-D extracted by DES and LLP-W extracted by hot water possessed the same sugar residues, such as 1,4-α-D-GalAp, 1,4-α-D-GalAMep, 1,3,6-β-D-Galp, 1,4-β-D-Galp, 1,5-α-L-Araf, and 1,2-α-L-Rhap, suggesting the presence of homogalacturonan (HG), rhamnogalacturonan I and arabinogalactan in both LLP-W and LLP-D. Notably, LLP-D was much richer in HG fraction than that of LLP-W, suggesting that the DES could assist to specifically extract HG from lotus leaves. Additionally, the lower molecular weight and higher content of uronic acids were observed in LLP-D, which might contribute to its much stronger in vitro antioxidant, hypoglycemic, and immunomodulatory effects. These findings suggest that the optimized DES assisted extraction method can be a potential approach for specific extraction of acidic polysaccharides with good bioactivities from lotus leaves for applications in the functional food industry.

Sequential natural deep eutectic solvent pretreatments of apple pomace: A novel way to promote water extraction of pectin and to tailor its main structural domains

To establish a "green" biorefinery extraction of apple pomace pectin, a sequential pretreatment with three natural deep eutectic solvents (NADES, choline chloride (CC): glycerol (G); CC: lactic acid (LA); potassium carbonate (K): G) was used prior to hot water extraction. A synergistic effect of CC:G and CC:LA pretreatments was observed and led to the highest recovery of pectin. The sequential NADES/water extraction process also provided a mean to tailor pectin main structure. It was explained as resulting from ion exchange and individual NADES components effects. The ¹³C solid state NMR T_1ρ^H and T_HH parameters indicated a reorganization of cellulose in the residues following extraction of pectin, notably after alkaline K:G pretreatment/water extraction. Hence, sequential NADES pretreatments/water extraction represents a "green" alternative to mild mineral acid to extract pectin and to tailor its main structures, while the residual pomace can be further sources of valuable compounds and polymers.

Novel extraction of polyphenols from sour cherry pomace using natural deep eutectic solvents - Ultrafast microwave-assisted NADES preparation and extraction

In this work, new approaches for the green extraction of polyphenols from sour cherry pomace were explored. Three Natural Deep Eutectic Solvents (NADES) systems based on choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and malic acid, urea, and fructose (MalA, Ur, and Fru) as hydrogen bond donors (HBD) were used. NADES systems were prepared by heating and stirring (H&S), ultrasound (US), and microwave (MW) methods. It was found that MW-assisted preparation was the fastest requiring less than 30 s. Polyphenol extraction from cherry pomace was performed also by three mentioned methods, and compared with conventional methods. MW extraction was the most rapid with less than 5 min necessary for the extract preparation. All three NADES systems were highly efficient for anthocyanin extraction, but the most efficient was ChCl:MalA system. Extract based on ChCl:MalA system was for 62.33% more efficient for anthocyanin extraction comparing with the conventional solvent.

Promising Technological and Industrial Applications of Deep Eutectic Systems

Deep Eutectic Systems (DESs) are obtained by combining Hydrogen Bond Acceptors (HBAs) and Hydrogen Bond Donors (HBDs) in specific molar ratios. Since their first appearance in the literature in 2003, they have shown a wide range of applications, ranging from the selective extraction of biomass or metals to medicine, as well as from pollution control systems to catalytic active solvents and co-solvents. The very peculiar physical properties of DESs, such as the elevated density and viscosity, reduced conductivity, improved solvent ability and a peculiar optical behavior, can be exploited for engineering modular systems which cannot be obtained with other non-eutectic mixtures. In the present review, selected DESs research fields, as their use in materials synthesis, as solvents for volatile organic compounds, as ingredients in pharmaceutical formulations and as active solvents and cosolvents in organic synthesis, are reported and discussed in terms of application and future perspectives.