Extraction Optimization of Morchella esculenta Polysaccharides by Response Surface Methodology and Its Antioxidant Activity

To research polysaccharide by enzymes-ultrasound assisted extraction technique and determined its antioxidant activity, the liquid-solid ratio, enzymatic hydrolysis pH, enzymatic hydrolysis time, ultrasonic time and enzyme dosage were optimized by Plackett-Burman experiment and response surface methodology. The results showed that the optimized technological parameters were as follows:Liquid-solid ratio 22:1 mL/g, enzymatic pH4.0, the enzymatic time 60 min, ultrasonic time 19 min, and the enzyme dosage 0.8%. Under these conditions, the actual crude polysaccharides yields was 7.79%. The protein removal rate by TCA method and the polysaccharides retention rate were 77.27% and 72.62%, respectively. The decolorization rate of AB-8 resin was 84.25% and the retention rate of polysaccharides was 95.71%. The scavenging activities of polysaccharides from Morchella esculenta on·DPPH,·OH and O₂^-·were reached 60.67%, 70.77% and 72.76%, respectively. The extracted polysaccharides had better antioxidant properties and could be developed into a new type of dietary supplement or functional food.