Rosenthal, I., Department of Food Science, Agricultural Research Organization, Volcani Center, POB 6, Bet Dagan 50250, Israel
Bernstein, S., Department of Food Science, Agricultural Research Organization, Volcani Center, POB 6, Bet Dagan 50250, Israel
Merin, U., Department of Food Science, Agricultural Research Organization, Volcani Center, POB 6, Bet Dagan 50250, Israel

Two commercial enzyme immunoassays, Ridascreen® and Rida® Quick CIS kits, recommended for the detection of adulteration of sheep and goat's milk, based on the recognition of bovine IgG, were evaluated for possible classification of bovine milk according to the thermal treatment. Our results confirm previous findings that the denaturation of IgG is markedly enhanced at temperatures above 73°C. In their present form, these assays may serve for the easy identification of UHT milk, and in conjunction with the phosphatase test, it provides a very convenient procedure for recognition of pasteurized and sterilized "in-bottle" milks, as well.