알콜 不安定乳에 關한 硏究

Studies on alcohol labile milk

This experiment has been carried out to study the physicochemical properties of labile milk on alcohol test which were yielded from healthy cows that they did not show the external clinical symptoms in the body and were in the normal lactation period. The results obtained were summerized as follows. 1) The cows yielding alcohol labile milk did not produce the positive milk on alcohol test always, and they did normal milk sometimes. 2) As the results of analysis on pH value, acidity, alizarin alcohol test, Whiteside test, heating test, chloride test and cell number, it seemed that there were little or no considerable differences between normal and alcohol labile milk. 3) The content of solids-not-fat, protein and lactose in alcohol labile milk showed values a little lower than those in the normal milk, and the content of fat and ash was similar to those of the normal milk. 4) Normal fresh milk frozen at-10℃ for 24 hours showed a tendency to be transformed into positive milk easily on alcohol test compared with the milk which the milk which was not frozen. 5) On the polyacrylamide gel electrophoresis, there was little difference between caseins made from normal and alcohol labile milk. 6) By rennet treatment on normal and alcohol labile milk, the milk clotting time, and the amount of soluble nitrogen at pH 4.6 and in 12% TCA were determined. However no significant difference was found between both of normal and alcohol labile milks. 7) Caseins obtained from normal and alcohol labile milks were tested by the different concentration of alcohol. As the result of the test, caseins from alcohol labile milk were precipitated easily compared with that of normal milk.