Abstract
Recrystallization phenomena in frozen foods hurt the quality. In this study, rates of recrystallization of ice in frozen foods were determined for red meats of tuna and tofu cakes. These samples were frozen in methanol brine at -50℃ and stored at -50, -30, -20, -5℃ for maximum 80 days. Mean diameter of ice crystals in frozen foods were observed by microscope after these samples were fixed by freeze-substitution method and then sliced to very thin samples. The rates of recrystallization were k=135×10^3exp(-18.69/RT) and k=26×10^3exp(-1.6/RT) for tuna fish meat and tofu cake, respectively. These values were smaller by thousand times than the Zaritky's results. Zaritky's results were obtained at -20℃ final freezing temperature. The difference of final freezing temperature caused large difference in the recrystallization rates. The lower the final freezing temperature make the better storage conditions for frozen foods.
