Internal temperature and softening rate of microwave cooked potatoes

The possibility of the prediction of cooking state in microwave cooking was discussed by cooking potatoes at definite temperature by intermittent application of electric current. The increase in the internal temperature of sample cooked in a microwave oven by a usual method proceeded in the order of the bottom, middle and top of the part of potatoes. The internal temperature reached 100℃ within 1min and 40sec to 3min. The intermittent heating was performed at definite temperature ranging from 67 to 97℃ and the changes in hardness were determined. The softening rate at each definite temperature was calculated from the changes in hardness with time. The rate constant k was given by k=3.301×10[13]exp (-1.175×10[4]/T) where T is temperature (K). The softening ratio was determined by using the internal temperature curves of sample and k at arbitrary cooking time. The softening ratio of calculated value almost agreed with that of experimental one while showing a difference of 13 to 19%. Thus it is suggested that the cooking ratio of microwave cooked potatoes can be approximately predicted with uslng its softening rate obtained by intermittent heating