Effects of packaging size and shape on the microwave rehydration characteristics of tilapia fillets

Abstract

In order to improve the rehydration rate and rehydration effect,the dried tilapia fillets( moisture content decreased to 0. 100 0( g / g d. b.)( dry basis)) w ere hydrated by microw ave. Tilapia fillets w ere put into the container made of acrylic materials w ith different sizes and shapes. The effect of container shape, container size,and salt content on the microw ave rehydration w as investigated. The result show s that the moistureed content increased gradually w ith the rehydration time extending,reached a maximum value and maintain stability after 250- 300 s. The moisture content of sample after rehydration process did not reach the initial moisture content( 3. 859 0( g / g d. b.)). It is show n that the rehydration process is irreversible, cell dehydration and damaged organizational structure during the drying process cause the rehydration ability of sample to decrease. In this study,the larger size of the container has a better rehydration effect. Compared w ith cubic container,cylindrical container is more advantageous to the microw ave rehydration for Tilapia fillets. The dielectric loss rate of soup material increased w ith the increasing of NaCl contents,so that the rehydration rate increased. In summary,rehydration time by microw ave is about 240 s,w hich saves about 2 / 3 time compared w ith the traditional w ater bath( about 700 s). Moreover,some models such as Peleg and Weibull model w ere used to fit the rehydration process. It w as found that Peleg model has a higher fitness for the experiment data than Weibull model. Peleg model w as more suitable for describing the rehydration process of tilapia fillets.