OPTIMIZATION OF CONTINUOUS MICROWAVE INACTIVATOR FOR POLYPHENOL OXIDASE INACTIVATION ON GREEN TEA PROCESSING USING RESPONSE SURFACE METHODOLOGY

Abstract

Microwave treatment is a promising technology for food processing such as drying, extraction, and enzyme inactivation because of its ionic heat transfer. This study develops and optimizes the fixation process in green tea using a microwave-based enzyme inactivator. A continuous microwave enzyme inactivator with a dimension of 3300 (L) × 550 (W) × 600 mm3 (H) was built to study the effect of temperature, microwave radiation time, and the number of microwaves on the catechin content of green tea. The optimum condition for the inactivation process was determined using response surface methodology and central composite design. The result shows that the model can predict the effect of temperature, microwave radiation time, and the number of microwaves on catechin content. Temperature, fixation time (conveyor velocity), and the number of microwaves, have a significant impact on enzyme inactivation when using a continuous microwave. The optimum microwave inactivation condition for polyphenol oxidase enzyme was four at 70C temperature and 30 rpm conveyor speed.