The Freezing of Rice Products in Box Containers: Temperature Profile Prediction, Model Validation and Physical Characteristics

Abstract

Abstract In this study, a three-dimensional finite difference method is applied to develop a mathematical model for the simulation of heat transfer phenomena in cooked white rice and fried rice in polypropylene boxes during the freezing process. The main objective was to develop a tool for predicting time/temperature profiles that can be applied under various freezing conditions. The results indicate fair agreement between experimental data and model predictions. The model precision can be improved if incorporating the heat transfer mechanism occurring at the head space and the equations for accurately estimating changes of freezing point temperatures and thermophysical properties of rice along freezing process. Textural properties of frozen rice samples after microwave warming were apparently different from the freshly cooked samples. Rapid freezing provided soft and nonsticky texture of cooked white rice after warming while slow freezing resulted in the fried rice with the most similar texture to freshly cooked fried rice.