STUDY ON EXTRACTION AND BIOLOGICAL ACTIVITY OF ANTIOXIDANT SUBSTANCE OF SWEET POTATOES / 营养学报

ABSTRACT

Objective: The chemical composition, extraction and biological activity of antioxidant substance of sweet potatoes were studied. Method: The antioxidant substance was extracted with alcohol and purified with AB-8 big-hole resin and its elimination rate of _?O 2 and OH and SOD activity were determined.Results: The content of antioxidant substance stockpiled respectively in the root tubers, stems and leaves of sweet potatoes and was different in varieties. The highest content in the root tuber was 0.324%, which accounted 70% of total content in sweet potatoes. Its extraction ratio was 85%. The major composition of the antioxidant substance was phenol acid, including chlorogenic acid,isochlorogenic acid,neochlorogenic acid and 4-0-caffeonyl quinic butyl ester. They had intense antioxidant function and their elimination rate to _?O 2 and?OH at concentration 90 mg/ml was 88.02% and 82.21% respectively. The antioxidantsubstance restrained oxidation of lipid and hemolysis of red cell induced by H2O2,and increased SOD activity in serum and skin of mice. Conclusion: Several kinds of phenol acid as antioxidant substance stockpiled in sweet potatoes were proved to have strong antioxidant activity.