Hygiene of Pasteurized Milk Depending on Psychrotrophic Microorganisms

Influence of storage temperature on the shelf life of the pasteurized milk and the enzymatic activity of psychrotrophic bacteria in whole and skimmed pasteurized milk were the main goals of the presented work. It was demonstrated that the storage temperature of 10C reduces the shelf life of pasteurized milk to one third in comparison with a storage at 4 C. The average shelf life of the full cream pasteurized milk reached 31 d at 4 C, the average shelf life of skimmed pasteurized milk was 32.57 d. At 10C the average shelf lives were 11 d for whole and 10.71 d for skimmed pasteurized milk. The evaluation of proteolytic and lipolytic enzyme activities produced by psychrotrophic microorganisms at different storage temperature showed increased activity of psychrotrophic microorganisms after 2 – 3 d at 10 C. Storage at 4C did not allow the production of comparable amounts of these enzymes for a three times longer interval.