Synergistic effect of thermosonication to reduce enzymatic activity in coconut water

Abstract

In order to minimize the depreciation of coconut water quality caused by the conventional heat treatment, non-conventional preservation methods have been studied. Ultrasound technology can be suitable as an alternative thermal treatment for several food matrices, due to its efficiency in microbiological and enzymatic inactivation. The objective of this work was to evaluate the effect of the thermosonication to reduce the enzymatic activity in coconut water and optimize the optimal operating parameters (amplitude and time) and corresponding specific acoustic energy required for the complete enzymatic inactivation. Ultrasound presented an additive effect to the heat treatment on the inactivation of the polyphenoloxidase (PPO) and peroxidase (POD). It was verified that from 500 to 550 mW/mL a great inactivation of the PPO and POD is achieved, already for a complete inactivation of these enzymes the specific acoustic energy necessary is 655.80 mW/mL. It was also verified that the both enzymes should be taken into account for a US process since PPO and POD presented very similar resistance.