Impact of different pasteurization temperatures on the survival of microbial contaminants isolated from pasteurized milk

Abstract

The thermal inactivation of selected microbes was studied using the low temperature long time (LTLT), high temperature short time (HTST) and ‘pot’ pasteurization methods. Survivors were enumerated after heating for up to 40 min for the LTLT and HTST pasteurization methods and after heating for up to 30 min for the ‘pot’ pasteurization method. With the exception of the Bacillus cereus strain, the selected microbes did not survive the LTLT and HTST pasteurization methods. The results from the ‘pot’ pasteurizer showed that B. cereus, Chryseobacterium meningosepticum, Pseudomonas putida, Acinetobacter baumannii and Escherichia coli strains survived the pasteurization conditions applied, showing that the ‘pot’ pasteurizer does not pasteurize effectively.