Deep Eutectic Solvent Extraction Research Articles

Exploring Phenolic Compounds Extraction from Saffron (C. sativus) Floral By-Products Using Ultrasound-Assisted Extraction, Deep Eutectic Solvent Extraction, and Subcritical Water Extraction.

Saffron (Crocus sativus) floral by-products are a source of phenolic compounds that can be recovered and used in the nutraceutical, pharmaceutical, or cosmetic industries. This study aimed to evaluate the phenolic compounds' extraction using green extraction techniques (GETs) in saffron floral by-products and to explore the influence of selected extraction techniques on the phytochemical composition of the extracts. Specifically, ultrasound-assisted extraction (UAE), subcritical water extraction (SWE), and deep eutectic solvents extraction (DESE) were used. Phenolic compounds were identified with (HR) LC-ESI-QTOF MS/MS analysis, and the quantitative analysis was performed with HPLC-PDA. Concerning the extraction techniques, UAE showed the highest amount for both anthocyanins and flavonoids with 50:50% v/v ethanol/water as solvent (93.43 ± 4.67 mg/g of dry plant, dp). Among SWE, extraction with 96% ethanol and t = 125 °C gave the best quantitative results. The 16 different solvent mixtures used for the DESE showed the highest amount of flavonoids (110.95 ± 5.55-73.25 ± 3.66 mg/g dp), while anthocyanins were better extracted with choline chloride:butane-1,4-diol (16.0 ± 0.80 mg/g dp). Consequently, GETs can be employed to extract the bioactive compounds from saffron floral by-products, implementing recycling and reduction of waste and fitting into the broader circular economy discussion.

Differential Extraction and Preliminary Identification of Polyphenols from Ugni candollei (White Murta) Berries.

Ugni candollei, commonly known as white murta, is a native Chilean berry with a polyphenol composition that has been underexplored. This study aimed to establish a comprehensive profile of white murta polyphenols using ultra-performance liquid chromatography electrospray ionization Orbitrap mass spectrometry (UPLC-ESI-ORBITRAP MS). Additionally, it compared the efficacy of conventional extraction methods with emerging techniques such as deep eutectic solvent (DES) extraction and hot pressurized water extraction (HPWE). The analysis tentatively identified 107 phenolic compounds (84 of them reported for the first time for this cultivar), including 25 phenolic acids, 37 anthocyanins, and 45 flavonoids. Among the prominent and previously unreported polyphenols are ellagic acid acetyl-xyloside, 3-p-coumaroylquinic acid, cyanidin 3-O-(6'-caffeoyl-glucoside, and phloretin 2'-O-xylosyl-glucoside. The study found HPWE to be a promising alternative to traditional extraction of hydroxybenzoic acids, while DES extraction was less effective across all categories. The findings reveal that white murta possesses diverse phenolic compounds, potentially linked to various biological activities.

Ultrasonication-assisted deep eutectic solvent extraction of flavonoids from pretreated fenugreek and their antidiabetic & hypo-lipidemic potential

Ultrasonication-assisted deep eutectic solvent extraction of flavonoids from pretreated fenugreek and their antidiabetic & hypo-lipidemic potential

Natural deep eutectic liquid and ultrasound-assisted extraction of milk thistle phenolics and their hepatoprotective activities

IntroductionThe present research describes the utilization of natural deep eutectic solvent in combination with ultrasound for the extraction of milk thistle polyphenols. The extracts obtained under different conditions were evaluated for their in vitro antioxidant activities and hepatoprotective activities in Albino mice (in vivo).MethodsThe extraction parameters involving liquid-to-solid ratio (S/L), ethanol-to-natural deep eutectic solvent ratio (EtOH/DES), extraction time (t), and ultrasound treatment time were investigated and optimized to enhance the recovery of bioactives, their phenolic content, Trolox equivalent antioxidant capacity (TEAC), and radical scavenging capacity (RSC).Results and discussionsThe extraction of milk thistle polyphenols using glucose/citric acid (1:1)-based natural deep eutectic liquid coupled with ultrasound for 1.0 min under an S/L of 6.2, EtOH/DES 9, and extraction time of 120.8 min offered 35.89 ± 2.29 g/100 g of crude extracts, which were three-fold higher than that by conventional solvent extraction (CSE). Each gram of milk thistle extracts thus obtained comprised 377.93 ± 6.17 mg GAE of TPC and exhibited 298.70 ± 3.06 μmol TEAC and 93.16 ± 0.58 percent inhibition of DPPH free radicals. In addition, the administration of milk thistle extracts obtained as given above at 25 mg/Kg body weight in Albino mice significantly (p ≤ 0.05) improved the liver function parameters at the end of treatment (7 days).ConclusionOverall, it was observed that NaDES in combination with medium-level ultrasound energy (700 watt) might work as a sustainable choice to enhance the recovery of bioactive phenolics from milk thistle powder without compromising their antioxidant and hepatoprotective potential.

Optimization of Ultrasound‐Assisted Deep Eutectic Solvent Extraction and Bioactivities of Polysaccharide from Porphyra haitanensis

AbstractIn this paper, ultrasound‐assisted method and deep eutectic solvent (DES) are used to extract polysaccharides from Porphyra haitanensis. The single‐factor experiment is carried out first, and then the response surface experiment is designed to obtain the optimal process conditions. The optimal extraction conditions are the molar ratio of choline chloride to oxalate of 1:1, the water content of DES of 60%, the solid–liquid ratio of 1:60 g mL−1, the time of 120 min, the power of 200 W, and the temperature of 80 °C, with the extraction yield of 4.42%. And the yield of P. haitanensis polysaccharides (PHPs) is 3.14% and 3.31% by water immersion and ultrasonic water extraction, respectively, indicating that the DES extraction method is superior to these two methods, and the optimization effect is good. The extracted polysaccharides are tested for biological activity after separation and purification on DEAE and Sephadex G‐75 columns. The results of α‐glucosidase inhibitory activity and α‐amylase inhibitory activity show that PHPs have certain antioxidant activity. 1,1‐Diphenyl‐3‐nitrophenylhydrazine (DPPH) and 2,2‐diazo‐di‐3‐ethylbenzothiazolin‐6‐sulfonic acid (ABTS) free radical scavenging assays show that PHPs have certain antiglycemic activity.

Anhydrous volatile fatty acid extraction through omniphobic membranes by hydrophobic deep eutectic solvents: Mechanistic understanding and future perspective

Volatile fatty acids (VFAs) derived from arrested anaerobic digestion (AD) can be recovered as a valuable commodity for value-added synthesis. However, separating VFAs from digestate with complex constituents and a high-water content is an energy-prohibitive process. This study developed an innovative technology to overcome this barrier by integrating deep eutectic solvents (DESs) with an omniphobic membrane into a membrane contactor for efficient extraction of anhydrous VFAs with low energy consumption. A kinetic model was developed to elucidate the mechanistic differences between this novel omniphobic membrane-enabled DES extraction and the previous hydrophobic membrane-enabled NaOH extraction. Experimental results and mechanistic modeling suggested that VFA extraction by the DES is a reversible adsorption process facilitating subsequent VFA separation via anhydrous distillation. High vapor pressure of shorter-chain VFAs and low Nernst distribution coefficients of longer-chain VFAs contributed to DES-driven extraction, which could enable continuous and in-situ recovery and conversion of VFAs from AD streams.

Separation of polyphenolic compounds from Citrus aurantium L. peel by deep eutectic solvents and their recovery using a new DES-based aqueous two-phase system

This study aims to investigate the extraction of polyphenolic compounds (PCs) from Citrus aurantium L. peel using Deep Eutectic Solvents (DESs) and ultrasound-assisted extraction (UAE). A screening process evaluated various DESs based on Choline Chloride (ChCl) with polyol, acids, and amides. ChCl-1,4-butanediol performs highest among the tested DESs and the benchmark solvent (70 % ethanol and water). The extraction efficiency, measured by total phenolic content (TPC) using the Folin − Ciocalteu method, was influenced by temperature, time, liquid-to-solid ratio, and water content. Optimal conditions were found at a temperature of 40 °C, extraction time of 30 min, water content of 49.95 %, and 18.97:1 solvent to biomass ratio with a yield of 7.85 mg gallic acid equivalent per gram of peel.Under these conditions, we employed an Aqueous Two-Phase System (ATPS) consisting of salt and DES to recover polyphenols from DES extracts. Various salts (K2HPO4, K3PO4, Na2SO4, LiCL, BaCl2, Na3cit, and NaCl) were assessed for their potential to form the ATPS. Among them, only K2HPO4, and K3PO4 demonstrated the ability to induce phase separation. The effect of the salt concentration was carefully investigated on the partitioning of the PCs. K3PO4 demonstrated a higher performance compared to K2HPO4 with an extraction efficiency of 88.54 %. An ATPS containing DES (0.67 % w/w) and K3PO4 (0.32 % w/w) proved advantageous for back-extraction. Water-immiscible organic solvents, including n-hexane, ethyl acetate, n-butanol, and isoamyl alcohol, were assessed as back-extraction agents. Notably, n-butanol achieved an impressive polyphenol recovery efficiency of 98.11 %.

Response surface optimization for deep eutectic solvents extraction of bamboo shoots proteins

To enhance the protein extraction rate of bamboo shoots, the Response Surface Methodology was utilized to optimize the protein extraction process of Chimonobambusa purpurea Hsueh f. & T.P.Yi (syn. Chimonobambusa neopurpurea T.P.Yi) bamboo shoots. Choline chloride and proline were utilized as hydrogen bond acceptors in a total of eight deep eutectic solvents, whereas glucose, sucrose, glycerol, ethylene glycol, acetylpropionic acid, malic acid, and lactic acid were used as hydrogen bond donors. This work examined the protein extraction from bamboo shoots using deep eutectic solvents. Single-factor experiments were conducted to determine the optimal composition of the deep eutectic solvents, along with the ideal gradients of material-liquid ratio gradients, water content, extraction time, and water bath temperature. The impact and interplay of various variables on the protein extraction rate of bamboo shoots were examined using the Box-Behnken Design and Response Surface Methodology. Both the water bath temperature and the extraction time significantly influenced the protein extraction rate of bamboo shoots. Notably, the interaction between extraction time and water bath temperature had the most substantial effect on the protein extraction rate of bamboo shoots. The quadratic response surface regression equation for the protein extraction rate of bamboo shoots relative to the actual values of each factor was obtained as follows: Protein extraction rate = −193.3275 + 3.8395 A - 18.7075 B + 6.3285 C + 0.2125 AB - 0.0089 AC + 0.024 BC - 0.02885 A2 + 0.685 B2 - 0.06455 C2. Finally, this work predicted optimum extraction parameters for bamboo shoots with choline chloride-sucrose (molar ratio 1:2), a material-liquid ratio of 1:50, a water content of 74 %, an extraction time of 4 h, and a water bath temperature of 44 ℃. Under the optimal conditions, the protein extraction yield was 59.39±0.45 %, which aligned with the predicted value from the response surface fitting equation. This indicated that the optimised regression equation may have practical significance. Compared with conventional extraction using a sodium hydroxide (NaOH) solution, deep eutectic solvents extraction of bamboo shoots is more environmentally friendly, non-toxic and harmless. It provides a theoretical and experimental reference for industrial extraction and offers a reference for deep eutectic solvent development in bamboo shoot resource utilization.Key message:To enhance the protein extraction rate of bamboo shoots, the Response Surface Methodology was utilized to optimize the protein extraction process of bamboo shoots.

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.

Recovery of Cembratrien-Diols from Waste Tobacco (Nicotiana tabacum L.) Flowers by Microwave-Assisted Deep Eutectic Solvent Extraction: Optimization, Separation, and In Vitro Bioactivity.

Deep eutectic solvents (DESs) are novel solvents with physicochemical properties similar to those of ionic liquids, and they have attracted extensive attention for the extraction of bioactive compounds from different plant materials in the context of green chemistry and sustainable development. In this study, seven DESs with different polarities were explored as green extraction solvents for cembratrien-diols (CBT-diols) from waste tobacco flowers. The best solvent, DES-3 (choline chloride: lactic acid (1:3)), which outperformed conventional solvents (methanol, ethanol, and ethyl acetate), was selected and further optimized for microwave-assisted DES extraction using the response surface methodology. The maximum yield of CBT-diols (6.23 ± 0.15 mg/g) was achieved using a microwave power of 425 W, microwave time of 32 min, solid/liquid ratio of 20 mg/mL, and microwave temperature of 40 °C. Additionally, the isolated CBT-diols exhibited strong antimicrobial activity against Salmonella, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa and antitumor activity in the human liver cancer HepG2 and SMMC-7721 cell lines. This study highlights the feasibility of recovering CBT-diols from tobacco flower waste using DESs and provides opportunities for potential waste management using green technologies.

Chestnut shell dyes extracted by deep eutectic solvent in green dyeing of silk fibers for enhanced washable, antibacterial and UV protection properties

As an important biomass resource, chestnut shells are often discarded and wasted. In this study, we report an innovative, low-cost and environmentally friendly approach of dyeing silk fibers with natural pigments extracted from chestnut shells using deep eutectic solvent (DES) and imbuing them with antibacterial and ultraviolet protection properties. To improve the extraction ratio of chestnut shell pigment, DES of choline chloride and urea (ChCl/Urea) with high solubility performance was adopted to extract pigment from chestnut shells and then directly used for silk dyeing. The color spectral curve, washing durability, antibacterial and ultraviolet resistance of dyed silk were tested and compared with the silk dyed by metal salt mordant. The result showed that compared with ethanol extraction, DES extraction method had a higher extraction rate and better stability of the extraction solution. Owing to the swelling, surface modification and high permeability of ChCl/Urea DES to silk fibers, the affinity between the pigment solution and silk fibers was enhanced, and the pigment molecules entered the amorphous area inside the silk fibers, forming a tight bond with the fiber matrix during dyeing. Therefore, the dyed silk fabric has excellent washing durability and soft luster, and the color strength (K/S) remained unchanged after three washings. Meanwhile, the antibacterial activity and ultraviolet protection coefficient of silk dyed with chestnut shell pigment reached above 97% and 42.26, respectively, which exhibits excellent antibacterial and ultraviolet protection properties.

Exploring deep eutectic solvent extraction's impact on anthocyanin degradation kinetics in various conditions

This study evaluated the stability of anthocyanins in red cabbage extracts using deep eutectic solvents (DESs) and acidified methanol under thermal and storage conditions. DESs included combinations of choline chloride with malic acid (Ma), xylitol (Xy), lactic acid (La), and glycerol (Gl). Extracts were heat-treated at 40 °C–100 °C and stored at temperatures of 25 °C, 4 °C, and −18 °C for 35 days. Analysis involved pH differential methodology, browning and polymeric color indexes, antioxidant assays (DPPH• and ABTS•+), HPLC, and FT-IR spectroscopy. Results showed that anthocyanin content in all solvents decreased with increasing temperature. Acidified methanol samples experienced a notable reduction from 304.2 mg/L at 40 °C to 246.5 mg/L at 100 °C. Malic acid, lactic acid, xylitol, and glycerol samples also showed significant declines at higher temperatures. Cold storage effectively preserved anthocyanin levels. Kinetic analysis indicated that ChCl-Xy was the most effective solvent in preserving anthocyanins and minimizing browning, while ChCl-Ma led to the highest anthocyanin degradation and color changes. At 25 °C, Ac-MetOH demonstrated the highest antioxidant activity (DPPH• scavenging rate k of 5.66 ± 0.15), but ChCl-Ma exhibited the highest browning index (k of 3.4 ± 0.13) and polymeric color index (k of 5.54 ± 0.12), suggesting lower stability compared to other solvents.

Improving the Composition and Bioactivity of Cocoa (Theobroma cacao L.) Bean Shell Extract by Choline Chloride-Lactic Acid Natural Deep Eutectic Solvent Extraction Assisted by Pulsed Electric Field Pre-Treatment.

An environmentally friendly method for the release of cocoa bean shell (CBS) extracts is proposed in this paper. This work aims to investigate the effect of pulsed electric field (PEF) pre-treatment on subsequent solid-liquid extraction (SLE) of metabolites with choline chloride-lactic acid natural deep eutectic solvent (NaDES) and bioactivity of cocoa bean shell (CBS) extract. Two different media for PEF application were evaluated: water and chlorine chloride-lactic acid. Total polyphenols (TPC), total flavonoids (TFC), individual major compounds, and antioxidant and antibacterial activity of CBS extracts were assessed. The performance of PEF-assisted extraction was compared with SLE and ultrasound-assisted extraction (UAE). The proposed method improved the release of TPC up to 45% and TFC up to 48% compared with the conventional extraction. The CBS extract showed medium growth inhibition of Escherichia coli and high growth inhibition of Salmonella sp, Listeria monocytogenes, and Staphylococcus aureus. Thus, an extract with enhanced antioxidant and antibacterial properties was obtained.

Valorization of biomass for food protein via deep eutectic solvent extraction: Understanding the extraction mechanism and impact on protein structure and properties

AbstractThe conventional techniques for protein extraction from biomass are not fully aligned with sustainability goals, so it is important to look for some alternate solutions. By simultaneously extracting both soluble and insoluble proteins, deep eutectic solvents (DESs) offer a viable method for valorizing protein‐rich biomass from a variety of sources. Notably, the molecular crowding effects of DESs may have helped unfolded proteins acquire compact and stable conformations, facilitating solubilization and effective extraction. However, there is still a lack of information regarding how DESs interact with proteins and affect the structure and properties of the recovered proteins. To enable their widespread usage as a sustainable method for extracting dietary proteins, the safety of DES‐extracted proteins must also be addressed. In this paper, we review the state of the science in DES‐mediated protein extraction, focusing on the extraction mechanism and the interactions between DESs and proteins. Additionally, important aspects of DES‐mediated protein extraction that could affect the structure, technofunctional, nutritional characteristics, and safety of extracted protein are explored. DES‐based protein extraction could be helpful to valorize different biomasses for the production of food proteins due to the specific features.

Artificial neural network optimisation of natural deep eutectic solvent extraction process of Danshen–Gegen and cytotoxicity study

Natural deep eutectic solvents (NaDESs) are environmentally friendly and efficient for the componential extraction of traditional Chinese medicine compared to conventional organic solvents. In this study, NaDES was screened and employed to extract Danshen–Gegen (DG), and the extraction process was optimised by response surface methodology (RSM) and artificial neural networks (ANN) model. Besides, the in vitro security of extracts of DG were evaluated in PC12 cells. As a result, Betaine-Urea (Bet-Ur) was screened as extraction solvent and ANN model was more accurate than RSM model in optimising the extraction parameter. The extraction process optimised by ANN was as follows: 70% NaDES concentration, 80 mg/mL solid to liquid ratio, 67 °C ultrasonic temperature, and 33 min of ultrasonic time. The comprehensive value of extraction yield was 0.7251 ± 0.84%. IC50 of Bet-Ur, NaDES DG extract and aqueous DG extract were 0.15%, 0.3% and 10% (v/v).

An efficient and environmentally-friendly extraction, characterization and activity prediction of polysaccharides from Rhizoma et Radix Notopterygii

Traditional hot water reflux extraction, ultrasonic-water extraction (UW), ultrasonic-natural deep eutectic solvent (NADES) extraction (U-NADES), ultrasonic-water and enzyme extraction (U-W-E) and ultrasonic-NADES and enzyme extraction (U-NADES-E) are employed for the extraction of Rhizoma et Radix Notopterygii polysaccharides (RNP), in which, the U-NADES-E has being proved as the most effective method. Response Surface Methodology (RSM) was utilized to optimize the conditions for U-NADES-E method. Using the optimal extraction conditions, the yield of RNP can be enhanced by nearly two-fold in comparison to the traditional extraction method, achieving a yield of 7.38 %, with a mere 30-min treatment and low ultrasonic power at 240 W. The RNP's composition included Rhamnose, Arabinose, Galactose, Glucose and Galacturonic Acid by high-performance anion-exchange chromatography. The polysaccharides from two different species of Rhizoma et Radix Notopterygii have also been characterized and identified. Network pharmacology and molecular docking predict that RNP may exert its effects in vivo through binding to PPARA, ACE and REN proteins, thereby potentially impacting diabetes outcomes. This study proposes a new, efficient, energy-saving and environmentally-friendly method for the extraction of RNP.

An Eco‐Friendly Approach for Determination of Lead in Biological Samples after Deep Eutectic Solvent Extraction

AbstractThe present research proposes investigating deep eutectic solvents for extracting Pb from biological samples for further determination by GF AAS. Among the synthesized solvents, the DES obtained from choline chloride and oxalic acid (ChCl : Ox) in a molar ratio 1 : 1 presented the best lead (Pb) extraction efficiency. Subsequently, it was characterized by Fourier Transform Infrared Spectroscopy (FTIR). For extraction, the optimized conditions were: 40 mg of sample, 400 μL of DES (ChCl : Ox) added, and 30 min at 95±5 °C. The supernatant was diluted, and the Pb was determined by GF AAS. The optimized instrumental conditions for Pb determination were 900 °C and 2100 °C, pyrolysis and atomization temperatures, respectively, using Pd as a chemical modifier. The limits of detection and quantification were 0.04 and 0.12 μg g−1, respectively. The method's accuracy was evaluated by analyzing the certificate reference materials, and good agreement was obtained between the determined and certificate values. The greenness of the proposed method was evaluated by green star and eco‐scale metrics. Thus, the proposed method proved simple, efficient, and eco‐friendly for determining Pb in biological samples.

Temperature-switchable deep eutectic solvent extraction of polysaccharides from wolfberry fruits: Process optimization, structure characterization, and antioxidant activity

Polysaccharides of wolfberry (LBPs) with complex structures are most commonly used in the food and pharmaceutical industries as biologically active phytochemicals. However, the structure and yield of LBPs vary according to the extraction method used, and selecting their extraction media remains difficult. A novel type of temperature-switchable deep eutectic solvent (TS-DES), consisting of L-menthol and phenyl salicylate, was designed to extract LBPs from wolfberry fruits. TS-DES was a recyclable extractant above the maximum critical solution temperature (UCST). The increased dispersibility of extraction solvents was imparted by combining them with a high-speed shear dispersion emulsification (HSDE) machine. TS-DES was in full contact with the cell walls of wolfberries, leading to the complete opening of the cell walls, resulting in the efficient extraction of LBPs. Compared with traditional extraction, the yield of LBPs-D reached 4.35%, which was higher than that of LBPs-W (1.78%). This study showed that LBPs-D were high molecular weight, highly branched polysaccharides with antioxidant activity. TS-DES was separated at a lower level than UCST for regeneration and reuse. After 5 cycles, TS-DES still had excellent recovery and extraction performance. This study provides valuable information for efficiently extracting structurally rich bioactive polysaccharides from plants using TS-DES.

Eco-Friendly and Efficient Extraction of Polysaccharides from Acanthopanax senticosus by Ultrasound-Assisted Deep Eutectic Solvent.

A green extraction method was developed using deep eutectic solvent extraction for the polysaccharide from Acanthopanax senticosus (A. senticosus). Among the eight types of DES prepared, the DES with a ratio of 1:4 L-malic acid to L-proline was found to be a suitable extraction solvent based on the extraction efficiency. The extraction parameters were optimized by Plackett-Burman and response surface methodology (RSM). The best extraction conditions were found for L-malic acid. Under the conditions of an L-malic acid/L-proline ratio of 1:4, ultrasonic power of 240 W, material-liquid ratio of 31.068 g/mL, water content of 32.364%, extraction time of 129.119 min, and extraction temperature of 60 °C, the extraction rate of A. senticosus polysaccharides was 35.452 ± 0.388 mg-g-1. This rate was higher than that of polysaccharides obtained by hot water extraction (13.652 ± 0.09 mg-g-1). The experimental results were best fitted by the quasi-secondary kinetic model when compared to two other kinetic models. Electron microscopic observations showed that DESs were more destructive to plant cells. The polysaccharide extracted from DESs had more monosaccharide components, a lower molecular weight, a higher antioxidant capacity, and superior anti-glycation activity compared to polysaccharides extracted from water (ASPS-PW). This study demonstrates the effectiveness of DESs in obtaining polysaccharides from A. senticosus.

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.