Abstract: The effects of external factors and five sterilizing processes on the stabilities of total antioxidant capacities (TAC) in three anthocyanin extracts of black rice, black soybean and black corn by colorimetry and ferric reducing ability method were investigated. The results showed that the TAC of anthocyanin extracts from seed coats of black rice, black soybean and black corn displayed the photosensitive characteristics that decreased with the prolonging of illumination; under the conditions of natural light, fluorescent light, and without illumination, the TAC stability was in the order of black rice anthocyanin (BRA), black soybean anthocyanin (BSA), and black corn anthocyanin (BCA); the TAC of these three anthocyanin extracts displayed the heat sensitive characteristics that decreased with the prolonging of heating time, and the higher the temperature, the more they were decreased; the TAC stability was in the order of BSA, BRA and BCA. There were no significant effects of food materials such as NaCl, sucrose, and glucose and preservative sodium benzoate on the TAC stabilities of these three anthocyanin extracts, while there were different effects of five metal ions of K+, Ca2+, Mg2+, Zn2+, and Cu2+ on the TAC stabilities of these three anthocyanin extracts; the TAC stabilities of these three anthocyanin extracts were significantly affected by five sterilizing processes of boiling sterilization, autoclave sterilization, pasteurization, microwave sterilization, and high temperature short time sterilization, of which they were least affected by high temperature short time treatment, and most affected by autoclave sterilization.

Key words: Anthocyanin, antioxidation, Stability