Application of Unsteady-state Heat Conduction Theory to Food Thawing Process

Because limited researches have been done so far on thawing of frozen foods, it is very important for keeping frozen foods of good quality to estimate food thawing time or changes in temperature profile during thawing period. In view of the fact that food thawing is caused by transition to the aqueous solution in food, we apply unsteady-state heat conduction theory including phase change for analyzing this thawing process. Since in the unsteady-state heat conduction equation the modified thermal diffusivity is related to the temperature, this equation shows intense non-linearity. It is difficult to solve this equation analytically, then we adopt to the collocation method. The calculated results were agreed well with the experimental data obtained from thawing tests of frozen food extracts. It is expected that this result would be useful for frozen food thawing operations.