[Chemical and microbiological studies of microwave-treated milk]

Pasteurized milk was treated with microwaves for 2.5 minutes (2450 MHz, 650 W). Important chemical components (vitamin A, beta-carotin, vitamins B1, B2, C, E; activity of peroxidase, xanthinoxidase; content of fat and peroxides, percentage of solids, content of raw protein, content of all microorganisms and storage stability were examined. Ascorbic acid (reduction of 36%) and alpha-tocopherol (reduction of 17%) were influenced by microwave treatment, whereas other chemical parameters, odor and flavor remained unchanged. The content of microorganisms was reduced from about 10(4) to 10(2) per milliliter. Untreated milk had a content of 10(7) microorganisms per milliliter after 10 days storage at 8 degrees C and a taste of acidity, whereas in milk treated with microwaves only 10(4) microorganisms per ml were identified and no organoleptic changes could be observed after 14 days storage at 8 degrees C.