Research of extraction and antioxidant activities of melanin in Auricularia polytricha from Qin-ba mountain area

The optimum technological condition of extracting melanin from auricularia polytricha and its antioxidant activities were researched.Melanin was extracted from auricularia polytricha through microwave-pretreatment and water- bath. The extraction technology was optimized through orthogonal experiment based on single- factor experiments.The results showed the optimum technological conditions as follows: the volume ratio of 1.25mol /L NaOH-95% ethanol was 1∶3, bathing temperature was 60℃, solid-liquid ratio was 1∶30, the reflux time was 70min.The experiment of antioxidant showed that the melanin had antioxidant activities, hydrogen peroxide clearance rate was up to 50% when the melanin's concentration was 0.4mg /mL, and the rate of scavenging free radical DPPH was up to 50% when the melanin's concentration was 0.18mg /mL, and the citric acid and the tartaric could enhance the antioxidant activities through the antioxidant experiment.