Studies on thermal destruction of Escherichia coli in milk and milk products.

Escherichia coli (ATCC no. 9637) was shown to have mean D values (slope of destruction rate curve) of 28.2, 5.1, 1.3, 0.00195, 0.00100, 0.00055, 0.00029, and 0.00016 min in milk at temperatures of 125, 130, 135, 168, 170, 172, 174, and 176 F, respectively. The mean D values for this organism in chocolate milk were 32.2, 10.4, 2.6, 0.00265, 0.00133, 0.00069, 0.00035, and 0.00028 min at respective temperatures of 125, 130, 135, 168, 170, 172, 174, and 176 F. Mean D values of 34.4, 10.0, 3.5, 0.00093, 0.00080, 0.00068, 0.00043, and 0.00036 min were found in cream for respective temperatures of 125, 130, 135, 168, 170, 172, 174, and 176 F. In ice cream mix the organism was found to have mean D values of 39.3, 15.2, 5.1, 0.00147, 0.00120, 0.00078, 0.00070, and 0.00053 min for temperatures of 125, 130, 135, 170, 172, 174, 176, and 178 F, respectively. The slopes of the thermal death time curves were found to be 10.2, 10.2, 10.0, and 10.3 F for this organism in milk, chocolate milk, 40% fat cream, and ice cream mix, respectively.