Effects of continuous flow microwave treatment on chemical and microbiological characteristics of milk

Raw cows' and goats' milks were heated by microwave in a continuous flow unit up to temperatures ranging from 73.1 to 96.7 degrees C. The effects of the heat treatments were estimated by measurements of lactose isomerization, protein denaturation, inactivation of alkaline phosphatase and peroxidase and the total bacterial count. Negative phosphatase tests and low bacterial counts, together with low degrees of whey protein denaturation, were achieved under several temperature/time combinations. The results indicate that continuous microwave processing may be an efficient and mild approach for the pasteurization of milk.