Abstract: The total activity is the main parameter to value the antioxidant ability of objects. Methods to measure total antioxidant activity can be divided into indirect and direct methods according to priciple, and indirect methods were fast and simple ways to determine the total antioxidant activity. At present, ABTS and DPPH were applied widely. The results of indirect methods were influenced by factors such as antioxidants and interactions, interference materials, pH, action time, producing system for free radicals and so on. Researchers tried to use the other advanced methods such as HPLC to decrease the environmental influence on the indirect method.

Key words: indirect method, ABTS, DPPH, antioxidant activity