In this study, the efficiency of various solvents and techniques was compared for the extraction of polysaccharides and antioxidants from Astragalus hamosus. Among twenty solvents and four extraction techniques, ultrasonic-assisted extraction using choline chloride-urea (a deep eutectic solvent, DES) demonstrated the best performance. Extraction variables were optimized by the response surface methodology (RSM), and Box-Behnken design (BBD). Extraction yield and total carbohydrate content (TCC) were 44.5% and 2.90 mgGlu/gdw, respectively. Rhamnose, mannose and galactose (molar ratio: 0.34:1.18:1.0) were major monosaccharides in the extracted polysaccharides. Six antioxidant assays—total phenolic content (TPC), total flavonoid content (TFC), DPPH assay, ferric-reducing antioxidant power (FRAP), trolox equivalent antioxidant capacity (TEAC), and reducing power assay (RPA)—were used to evaluate antioxidant capacity. Additionally, different extraction methods, including ultrasonic-assisted, microwave-assisted, maceration, and Soxhlet extractions were compared.
Tabaraki et al. (2025) studied this question.