Optimization of extraction process of polysaccharides from Lycium barbarum pomace and in vitro analysis of antioxidant activity

Objective To improve the utilization rate of Lycium barbarum fruit pomace, the extraction process of Lycium barbarum fruit pomace polysaccharide was optimized.

Methods Taking Lycium barbarum fruit pomace as the research object, the extraction process of Lycium barbarum fruit pomace polysaccharides was optimized by using a factorial design combined with Box-Behnken response surface method, and afterwards, the antioxidant activity of the polysaccharides was investigated in vitro.

Results The best extraction process was as follows: extraction temperature of 44°C, ultrasonic time of 44 min, alcohol sedimentation concentration of 78%, liquid material ratio of 1∶21 (g∶mL) and alcohol sedimentation time of 12 h. The actual polysaccharide yield from Lycium barbarum fruit pomace was 6.81 ± 0.24%, which was close to the prediction value of 6.95%. In vitro antioxidant assays showed that the clearance of DPPH and ABTS⁺ was 73.69% and 57.68%, respectively, and the FRAP value was 3.02 when the concentration of the polysaccharide solution was 5.0 mg/ml.

Conclusion The optimized process for the extraction of crude polysaccharides from Lycium barbarum fruit pomace is stable and has a strong antioxidant capacity.