The effect of supercooling-freezing on inhibition of ice recrystallization during storage.

In this paper, the effect of supercooling-freezing (freezing via supercooling) on ice crystal recrystallization in tofu (soybean curd) during frozen storage was investigated. The ice crystal growth rate by recrystallization depends on the storage temperature; however, there is an assumption that the size of ice crystals influences the ice crystal growth rate, and the assumption was investigated. Using a conventional freezing method, the ice crystal size of surface and center of food tends to be different. In contrast, supercooling-freezing is known to form minute and nearly uniform ice crystals in food. Each sample was frozen by rapid freezing(R), supercooling-rapid freezing (SR), and supercooling-slow freezing (SS) to observe the difference of ice crystals growth. The samples were preserved for up to 1 month at several temperatures. From the X-ray CT images, characteristics of ice crystals were observed, and the growth rate of ice crystal was calculated for each freezing method.