Inhibitory Effect of Ultra-high Pressure Treatment on Polyphenol Oxidase and Peroxidase Activities in Banana Pulp

In order to minimize residual polyphenol oxidase (PPO) and peroxidase (POD) activities in banana pulp after ultrahigh pressure treatment, the effects of pressure, temperature and pressure holding time on PPO and POD inactivation in banana pulp were dealt with using single factor and quadratic orthogonal rotation combination design methods. Results showed that the above factors decreasingly affected residual PPO and POD activities in the following order: pressuretemperaturepressure hold time and temperaturepressurepressure hold time, respectively. The optimal values of the above factors leading to 0.90% residual PPO activity and 3.26% residual POD activity were identical, 480 MPa held for 10 min and 55 ℃.