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Page No. : 97-102

ABSTRACT

Microbial quality assessment in the production of pasteurized milk (60) was done by evaluating milk samples during various stages of pasteurization viz. immediately after heating, after pasteurization and after packaging (20 each). The mean TVC was high in packaged milk and the difference between the mean TVC of milk obtained from various stages of pasteurization was highly significant (p<0.01). Coliform organisms were absent in all heated milk samples. However, 20% of milk after pasteurization and 60% of milk samples after packaging revealed the presence of the coliform organism and the difference was highly significant (p<0.01). The Esherichia coli count was detected only in 10% packaged milk (mean count 0.31± 0.21). Psychrotrophic organisms were found in heated milk and showed highly significant (p<0.01) variation from the count of pasteurized and packaged milk. The faecal streptococcal count was minimum in heated milk and maximum in packaged milk and the difference between the mean count of the samples was highly significant (p<0.01). Significant (p<0.05) difference in the yeast and mould counts of pasteurized milk and packaged milk and also between pasteurized and heated milk was obtained. E. coli (serotype 0148) and S. aureus was isolated from 2 (10%) and 1 (5%) pasteurized milk samples, respectively, however, none of the sample revealed the presence of L. monocytogenes. Among the hazards assessed (viz. air, water, hand wash, equipment wash and package material) maximum TVC was seen in the washings of packaging equipment and working personnel. Tap water and storage crate also showed high microbial count.

Keywords: Critical control points, microbial quality, milk, pasteurization