Ascorbic acid oxidase (Ascorbate oxidase, AO), referred to as: ASO, belongs to the family of ceruloplasmin, molecular weight is 140kD, composed of two identical subunits (70kD), the oxidation of ascorbic acid to dehydroascorbic acid, accompanied by oxygen to form water, and other redox reaction is coupled to the terminal oxidase role, oxidation can catalyze ascorbic acid, has anti-aging effect, has an important role in the metabolism of plants.