Enzymic hydrolysis of ginkgo albumin protein and its antioxidant activity

Ginkgo Albumin Protein (GAP) was separated from Ginkgo seeds for the first time by Natural Products Lab of Huazhong Agricultural University, which exhibited remarkable biological activity in former studies. In order to improve its biological activity and use in food industry, preparation method of ginkgo peptides from GAP by enzymatic hydrolysis and change of antioxidant activity were studied. The optimal conditions for enzymatic hydrolysis were obtained by single factor analysis and then orthogonal experiment: the substrate concentration was 1% and the enzyme concentration is 7000 u per gram of substrate; the hydrolysis process was performed under 45℃, pH 8.5 for 6 h. Scavenging abilities of superoxide radicals and hydroxyl radical of GAP and Ginkgo peptides were evaluated in Fenton system and pyrogallic acid system. The results showed that GAP and Ginkgo peptides both exhibited strong antioxidant activity and the activity of the peptides was higher than GAP's at the same concentration.