Study on microwave assisted extraction and purification of resveratrol from grape leaves

Cabernet Sauvignon grape leaves collected from Bazhou area in southern Xinjiang were used as the subjects to extract resveratrol through microwave assistant method,and NKA- Ⅱ resin for purification.Experiments showed that the optimum technological conditions for extraction of resveratrol from grape leaves assisted by microwave method were ethanol concentration 40%,microwave power 640 W,extraction time 76 s,ratio of solid to liquid 1∶92. Under these conditions,the extraction of resveratrol was 13.52 mg/g. Through the static test screening,resveratrol the crude product was purified using NKA-II resin. The optimum technological conditions were as follows:the sample solution volume was 6 BV,the concentration of resveratrol 3 mg/m L,the p H of absorbing stock solution was 4,the dynamically absorbing rate of flow was 2 BV/h,with four times the column volume of,90% ethanol solution as desorption agent under flow rate 3 BV/h. And the purity increased from 35.7352 mg/g to 181.5888 mg/g. Conclusion:Although the extraction rate of microwave assisted method was not the highest,but the time was short,and was suitable for industrial production,purification although had certain effect,but still need further research.