USE OF SELECTED STARTER CULTURES IN THE PRODUCTION OF FARM MANUFACTURED GOAT CHEESE FROM THERMIZED MILK

The effect of thermization and selected starter addition on the microb iological and chemical characteristics of farm manufactured goat chees e was evaluated. The starter cultures (Lactococcus lactis ssp. lactis, Lactobacillus casei ssp. casei and Lb. helveticus) were selected on t he basis of their acidifying activity. This was assayed using the diff erent strains as pure cultures or as different associations in sterili zed goat milk. A fourth degree polynomial was used to determine the ma ximum instantaneous acidification rate and the time and the pH at whic h it occurred. Thermization completely or almost completely eliminated staphylococci and coliform organisms despite the high raw milk contam ination. However, recontamination occurred even though starter culture s gave good acidification. All the species added as starter were reiso lated from the thermized milk cheeses. Among the enterococci, Enteroco ccus faecium, and E. durans were isolated most frequently; more than 5 0% of staphylococci were Staphylococcus epidermidis and S. hyicus, 10% were S. aureus (from raw milk cheese only). Yields and chemical compo sition of raw and thermized milk cheeses were similar, except for a hi gher non-casein N/total N ratio in the former. Sensory analysis rated thermized milk cheeses as less eyed and goaty, moldier, whiter, harder and slightly bitter.