Ultrasound-Assisted Deep Eutectic Solvent Extraction of Polysaccharides from Anji White Tea: Characterization and Comparison with the Conventional Method

Abstract

Deep eutectic solvent as a new green and safe solvent system has attracted more and more attention in recent years. In this study, three deep eutectic solvents (DES) were combined with ultrasound irradiation to extract tea polysaccharides (TPs) from Anji white tea, which was compared with conventional hot water extraction (HW). The physicochemical, structural, and biological properties of TPs extracted by ultrasound-assisted DES and hot water (HWP) were further investigated. Results showed that the DES system composed of choline chloride and 1,6-hexanediol (CH) with the molar ratio of 1:2 exhibited the optimal extraction yield (19.18%) and in vitro antioxidant activities for TPs (CHP). Furthermore, compared to the HWP, the CHP had a higher extraction yield and total carbohydrate content and a lower molecular weight. Monosaccharide composition analysis displayed that the molecular structure of CHP exhibited more arabinose but less glucose, mannose, galacturonic acid, and glucuronic acid than HWP. Little difference was observed in the preliminary structural characteristics between HWP and CHP from Fourier transform infrared analysis. Besides, CHP possessed better α-glucosidase inhibitory and hypoglycemic activity in L6 cells than HWP. Therefore, the ultrasound-assisted DES extraction method can be a promising strategy for extracting TPs with excellent bioactivities for future applications in functional foods.

Exploring carbohydrate extraction from biomass using deep eutectic solvents: Factors and mechanisms

“… 140 Anji White Tea Choline Chloride: 1,6-Hexanediol 1:2 40°C, ultrasonic time: 40 min, ultrasound TPs 19.18% Xia et al. 141 Lithocarpus litseifolius Choline Chloride: Urea 3:1 11.0 min, water content: 21%, L/S = 29 mL/g, extraction power:576.0 W. Total sugar (4.16% ± 0.09%) Wu et al. 142 Radix Bupleuri Choline Chloride: Urea 3:1 57.34°C, water content: 20%, L/S = 30, ultrasonic power: 400 W, pH = 4.89, and the amount of enzyme was 2.63%.…”

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

“…Because of its unique edible and medical value, Lentinus edodes has become a favorite edible fungus in many countries, especially in the eastern region of Asia [1] . The biological activities of Lentinus edodes are quite diverse, including anti‐oxidation, anti‐tumor, and immune regulation effects [2–4] . The expression of these biological effects is attributed to the fact that it contains many different nutrients, including polysaccharides, proteins, dietary fibers and lipids, among others [5,6] .…”

Density-oriented deep eutectic solvent-based system for the selective separation of polysaccharides from Astragalus membranaceus var. Mongholicus under ultrasound-assisted conditions

“…There are many advantages to the study of extracting plant polysaccharides with deep eutectic solvents in aqueous solutions, such as the high hydrogen bonding ability between deep eutectic solvents and polysaccharides, which improves the solubility and extraction efficiency of macromolecular polysaccharides in solvents [33] , [34] , [35] . Zhang et al extracted polysaccharides from Dioscorea opposita Thunb using a DESs composed of choline chloride and 1,4-butanediol, with a polysaccharides yield of 15.98%, far superior to that of hot water extraction [36] .…”