An Effective Method of Quality Improvement of Raw Milk and Its Practical Application

Abstract

It was demonstrated that raw milk could be improved in quality when it was tested separately by batch from each farmer. The resazurin test was presumed to be the most fitted for this purpose. In this test, resazurin test paper was used at 37°C for an hour. When a sample of raw milk changed the color of this paper to disc No.2 (muncell color, 2.5; RP, 9/2) or below, it was regarded as substandard milk. When it changed the color of this paper to disc No.3 and above, it was regarded as milk passing the standards. In the same batch of raw milk, the rate of occurrence of substandard milk as determined by the resazurin test did not significantly differ from that of milk containing more than 4 million bacteria as determined by direct microscopic individual counting. Accordingly, the proposed criterion based on the results of the resazurin test was assumed to be reasonable.