Optimization on extraction process of resveratrol by intermittent ultrasonic assisted enzymatic extraction from grape skin residue

Objective: In order to efficiently extract resveratrol and to maintain the good antioxidant capacity. Methods: Resveratrol was extracted from grape skin residue using intermittent ultrasonic assisted enzymatic extraction. The response surface method （RSM） was utilized to optimize the extraction process, and the antioxidant capacity of resveratrol were analyzed. Results: The experiment results indicated that under the condition of buffer solution pH of 5.0, cellulase dosage of 1.3% and enzymolysis temperature of 57 ℃, the resveratrol obtained better extraction effect after intermittent assisted treatment with 300 W ultrasonic waves for accumulatively 43 min, and the average yield could reach 0.293%. The antioxidant analysis found that the resveratrol had obvious scavenging effect on DPPH·, ·OH and ABTS·, as well the total antioxidant capacity was better. Conclusion: The resveratrol extracted by intermittent ultrasonic assisted cellulase method, both the yield and antioxidant capacity have been greatly improved comparing with the single enzymatic method or continuous ultrasonic extraction.