Pseudosclerotia of Sparassis latifolia are an underutilized by-product and a promising source of functional polysaccharides. This study compared hot-water extraction (HWE) with ultrasound-assisted extraction (UAE) and optimized UAE using response surface methodology. The optimized process (480 W, 72 min, 58 mL/g) increased yield to 39.91%, compared with 29.89% for HWE. Fourier-transform infrared spectroscopy and X-ray diffraction indicated that UAE preserved the main structural features and retained a predominantly amorphous structure, while HPGPC and monosaccharide analysis indicated a lower molecular weight and slightly different monosaccharide molar ratios; both fractions were mainly glucose-rich. Microscopic and colloidal analyses showed a looser microstructure, smaller particle size, and improved dispersion stability (higher absolute zeta potential). Functionally, the ultrasound-derived polysaccharide displayed stronger in vitro antioxidant capacity and inhibited α-amylase and α-glucosidase at 3.0 mg/mL. These results demonstrate that UAE is an efficient, non-derivatizing strategy to valorize S. latifolia pseudosclerotia into functional polysaccharide ingredients for food-related applications. • • S. latifolia pseudosclerotia were explored as an underutilized polysaccharide resource. • • Optimized UAE increased SLPP yield to 39.91%, compared with 29.89% for HWE. • • UAE-SLPP exhibited stronger in vitro antioxidant and digestive enzyme inhibition. • • RSM-optimized UAE offers a green and efficient strategy for valorizing mushroom by-products.
Qiu et al. (Fri,) studied this question.