Study on the extraction optimization and antioxidant activity of polysaccharides in gonad of Sepia lycidas

Using the gonad of Sepia lycidas as raw material,optimization of extraction polysaccharides process was studied by using Box- Behnken design based on the results of single- factor test; antioxidant activity of polysaccharides was evaluated by its superoxide anion and hydroxyl free radical scavenging abilities.The results showed that the optimal extraction parameters were as follows: 1∶30g / m L for ratio of raw material to water,90℃ for extraction temperature,and 1h for extraction time. Under the optimal conditions,the extraction rate of polysaccharides was 0.751%.The polysaccharides had good abilities to scavenge hydroxyl and superoxide anion free radical.It was indicated to a positive correlation with concentration of polysaccharides. IR spectrum showed that the polysaccharide was pyranoid glucan with β- glycosidic bond.