우유의 보존온도에 따른 listeria monocytogenes의 거동

Behavior of listeria monocytogenes in various milk during storage at 5, 25 and 35℃

In order to find growth and survival of L. monocytogenes on the stored temperature of milks, attempts were made to determine counts of survival cell and pH in various milk inoculated with this organism during storage at 5, 25, and 35℃. The initial counts of L. monocytogenes were 10⁵CFU/ml and were reduced to 10³CFU/ml in raw milk after 12 days of storage at 5℃, whereas, were increased to 10⁶-10⁹CFU/ml in pasteurized milk, sterile milk, and skim milk. In raw milk, viable cell counts were 10⁹CFU/ml and the pH was decreased to 5, 12 after 12 days of storage at 5℃. In pasteurized milk, sterile milk, and skim milk, viable cell counts were similar to those of raw milk and the changes of pH were not recognized. Thus, e higher temperature went up, the higher e death rate of L. monocytogenes became in raw milk. According to the result above, it seems that milk and milk products contaminated with L. monocylogenes are very remarkable carrier of foodborne infection.