[Use of the pyruvate test for determining the bacterial activity in milk].

Comparative studies were carried out on the pyruvate and reductase tests applied in milk of varying hygienic properties. It was established that: just after milking the pyruvate and reductase tests have a low correlation with bacterial infestation of milk; in milk cooled at 3--5 degrees C for a longer period (72 h) the pyruvate test has a good correlation with bacterial infestation of milk; following storage of milk at temperature above 10 degrees C the reductase test with methylene blue is better correlated with bacterial infestation of milk; the pyruvate-test is appropriate for evaluation of bacterial activity in milk cooled at low temperature and transported every second day; the reductase test is appropriate evaluation of bacterial activity in not well cooled milk which is transported one a day.