Effects of high temperature and pH on the antioxidant activity of the anthocyanins in Vaccinium uliginosum

The object of this study was to evaluate the effects of different heat-up time ( 6, 8, 10min heating at 121℃) and pH on the antioxidant activity and the contents of the anthocyanins in Vaccinium uliginosum. The results showed that Monomeric anthocyanin ( MA) 、Secondary color anthocyanin ( SCA) 、Polymeric anthocyanins ( PA) and Total anthocyanins ( TA) tended to decrease with the increasing of heat-up time and pH.The content of SCA was detected only in pH4.0⁵.0. The residual rates of anthocyanins reduced with the increasing of heat-up time and pH.The results of DPPH·showed that, in the same pH, the activity of scavenging DPPH·were 6min > 8min > 10min and all reached to the best at pH1.0 with the values of IC 50 were 1.50, 2.94, 3.40μg /mL respectively.The results of ABTS+·showed that, under pH1.0 and 6, 8, 10min heating at 121℃, the values of IC 50 were 0.27, 0.29, 0.32μg /mL, respectively; the scavenging ability tended to decrease with the increasing of heat-up time and pH.