Survey of the Microbiological Quality of Adult Bovine Rennet Extracts

Sixty-nine samples of liquid bovine rennet extract from several cheese-making plants were examined for microbiological quality. Wide differences were observed in the microbiological results, as well as in the pH, which ranged from 4.0 to 6.5, reflecting the manufacturing practices and sanitary conditions. The highest level of contamination was always caused by sporulated bacteria, both aerobic and anaerobic. Coliforms, considered to be enteric indicator bacteria were not detected, although halotolerant bacteria were found.