Enhancing the black truffle polysaccharide extraction efficiency using a combination of natural deep eutectic solvents and ultrasound-assisted techniques

Natural deep eutectic solvents (NaDESs) with ultrasound-assisted (UAE) method was used to improve the extraction efficiency of polysaccharide from black truffles, which can overcome the limitations of conventional methods. It demonstrated that the extraction efficiency of polysaccharide by six NaDESs with UAE were better than those of conventional solvents. Among the NaDESs, betaine-citric acid (BetCi) NaDES showed the best performance, achieving a remarkable extraction yield of 9.38%, outperforming water, ethanol, and 1,3-butanediol by 0.4, 11.5 and 11.0 times, respectively. Moreover, the polysaccharide yield was further optimized by response surface method, based on three influence factors (NaDES concentration, liquid-to-solid, and ultrasonic time). Scanning electron microscopy images showed that compared to the traditional extraction methods, the plate-like structure fractured into smaller pieces of black truffles treated by BetCi NaDES with UAE, indicating deeper interactions between NaDES and black truffles. Furthermore, the skin penetration as well as antioxidant and anti-wrinkle properties of the black truffle polysaccharide extract were evaluated, revealing promising bioactivity. Overall, this study represents a comprehensive exploration of novel extraction methods, highlighting efficient polysaccharide extraction and its potential applications.