Study on the Passivation of Polyphenol Oxidase and Peroxidase in Mango by High Field Ultrasound

The inactivation of mango polyphenol oxidase(PPO) and peroxidase(POD) by heating or ultrasound alone or combination of the two was studied.The results indicated that the PPO and POD activities decreased gradually with the increase of time when treated with heating(≤50 ℃) or low temperature ultrasound at 0 ℃(403.19 W/cm~2、601.25 W/cm2~ and 799.31 W/cm~2) alone,and the residual activity(RA) was above 75%.However,PPO and POD were significantly inactivated by the combination of heating and ultrasound.The RA of PPO and POD decreased to 38.66%and 14.43% respectively after 15 min treatment at 799.31 W/cm~2 and 45 ℃.The results indicated that the combination of ultrasound and heating had a synergistic effect on the inactivation of mango POD and PPO.