The inactivation kinetics of polyphenol oxidase and peroxidase in bayberry juice during thermal and ultrasound treatments

Ultrasound is a non-thermal food processing method for microorganism and enzyme inactivation, as well as quality maintenance. Attractive color is one of the most important quality attribute of bayberry products and strongly affects the consumer acceptance and preference. A key role in color degradation in berry fruit products is attributed to enzymatic browning of phenolic compounds which mainly related to PPO and POD. Therefore, the inactivation of PPO and POD is necessary for better color retention and shelf life increasing. This study would provide technical support for PPO and POD inactivation of ultrasound technique in bayberry juices processing.