Abstract:  An optimum detecting method in vivo was constructed for evaluating antioxidant ability of functional food. A proper condition was selected by investigating several factors as follows: given modes of hydroxyl radicals trapping agent(salicylic acid), measurement of trapping time period, sensitive drug responded tissue, extraction method of a variety tissue samples, and HPLC separation condition. The experiment was carried out in healthy mice age>10 months. The mice were divided randomly into 2 groups, 10～15 mice for each group. Fed one group with functional food, and the other as control. After 50 days of oral administration for functional food, salicylic acid was injected into the mice tail vein. 60 minutes later, animals were decapitated and liver was rapidly dissected. Hydroxyl free radical level was quantified by measuring the hydroxylation products. 2,3-and 2, 5-dihydroxybenzoic acids (DHBA)formed as a result of the reaction between· OH and salicylate. Then, DHBA and salicylate concentrations were determined using RP-HPLC with UV detection. Compared data from the 2 groups, to determine the antioxidant ability of the functional food. In addition, experiment of oral administration of vitamin C in mice proved the feasibility of this method.

Key words: antioxidant functional food, evaluation method for function food, hydroxyl radicals, salicylic acid trapping