The Destruction Rate of Psychrophilic Bacteria in Skimmilk

Abstract

Psychrophilic counts on commercially pasteurized milk varied from less than 1 to 30/ml. 24 hrs. after pasteurization. The rate of development in milk varies considerably; this is an important factor in deter-mining the keeping quality of milk. The z values of Pseudomonas mephitica and P. viscosa 3 obtained from phantom thermal death time curves were 7 and 14, respectively. Comparing these values with that of the standard milk pasteurization curve indicates that these organisms are destroyed by both low-temp, long-time and high temp, short-time pasteurization processes.O.