2017 Volume 34 Issue 1 Pages 25-
Supercooling phenomenon is focused as one of methods to suppress expansion of ice crystal size by freezing. So, the purpose of this research is to investigate the relation between cooling condition and ice crystal size experimentally, and find a cooling condition to suppress the expansion of ice crystal size. Tuna was selected as a specimen. As a result, temperature distribution at the instance of freezing was obtained by simulation, and the relationship between ice crystal size and the temperature distribution was clarified by comparing with an image of X ray CT scan. It was found that expansion of ice crystal size exists at the region having the temperature above -4℃ which is the degree of supercooling of 2.3K for tuna. Temperature of around -5℃ was found to be the limited boundary to sustain a supercooling and freezing may occur at region where the temperature is below this point. Furthermore, by introducing the model in the previous report to find the probability of freezing, the possibility to obtain a suitable cooling condition for various sizes and aspect ratios of food to suppress the expansion of ice crystal size by food freezing was presented.
