THE INFLUENCE OF ENVIRONMENT AND PROCESSING ON SPOILAGE ORGANISMS IN COTTAGE CHEESE1

Abstract

Microbiological analyses were performed on samples taken at various stages of processing of 17 vats of cottage cheese manufactured in 12 commercial plants. In 10 vats of fresh cheese whose shelf-life ranged from 5 to 10 days, the logarithmic averages of the counts of coliform, lipolytic and proteolytic bacteria were 50, 1,298 and 1,967 percent greater than the corresponding averages of 7 vats whose shelf-life ranged from 13 to 16 days. Spoilage organisms were found in water, coagulator, starter, air, contaminated equipment and improperly pasteurized milk and cream. Several water supplies contained high populations of lipolytic and proteolytic organisms, but were free of coliform bacteria which are commonly used as an index of acceptability for water supplies.