Green Extraction of Polysaccharides from Gleditsia japonica Var. delavayi Seeds: Optimization and Physicochemical...

The endosperm of Gleditsia japonica var. delavayi seeds is a valued medicinal and edible material, rich in polysaccharides exhibiting excellent functional properties for food applications. However, conventional methods for extracting Gleditsia japonica var. delavayi polysaccharides (GJP) are often inefficient and environmentally unfriendly. Thus, we developed a green, ultrasound-assisted process for extracting GJP. We systematically optimized key parameters (liquid-solid ratio and ultrasonic time, temperature, and power) using single-factor, Plackett-Burman and Box-Behnken experimental designs to maximize yield and characterize the product. The optimized process (200 mL/g, 62 min, 51 °C and 180 W) exhibited an extraction yield of 76.11%, producing GJP with a purity of 79.89%, which satisfies standards for food additives. The extracted GJP exhibited a semi-crystalline structure, high solubility (80.06%), low esterification degree (2.60%) and high viscosity and thermal stability between 30 °C and 70 °C. Crucially, this process required no chemical reagents and consumed only 0.18 kW·h of energy. Analysis indicates that the optimized ultrasound-assisted extraction of GJP is a green and efficient method with high extraction rates and reduced processing time and energy consumption; furthermore, it does not require any chemical reagents, making it a promising alternative to conventional techniques.