A THEORETICAL COMPARISON OF LOSSES IN FOODS UNDER FLUCTUATING TEMPERATURE SEQUENCES

The prediction of shelf life of foods is dependent on certain physical factors which change as a function of time in distribution. Temperature has been the most studied factor. With respect to fluctuating temperature studies in all cases in the literature, a zero order reaction rate has been assumed. In actuality, many foods degrade by first order rates thus the equations for prediction of losses are incorrect if applied. New equations for first order degradation have been developed. Comparisons for losses in a theoretical temperature distribution show that for less than 50% degradation the losses are about the same for zero and first order at anytime, thus determination of the order is not critical. This study shows that the temperature sensitivity (Q₁₀) of the reaction is very important in making predictions.