Study on Microwave-Assisted Extract and Antioxidant Activity of Ginger Flavonoids

Microwave-assisted extract process for flavonoids from ginger (FG) was studied. Influences of concentration of extracting agent, microwave power, material ratio and irradiation time on the extraction were investigated. From orthogonal experiments the optimum extracting parameters were determined as follows: microwave power, 640W, concentration of alcohol, 80%, the materials ratio, 1:30 (W: V) and irradiation time, 25s. Under this optimal condition, the yield of flavonoids was 16.97 mg/g. In this study, the antioxidant activity of FG was evaluated by various methods with BHT and ascorbic acid as control standards. Antioxidant experiments showed that FG exhibited a strong DPPH radical scavenging activity, reducing power and inhibition of lipid peroxidation activity, and antioxidant activity increased with increasing concentration.