PROTEOLYSIS AND VOLATILE COMPONENTS OF REDUCED-FAT CHEESES MADE FROM ULTRAFILTERED MILK AND DIFFERENT STARTERS SUPPLEMENTED WITH LACTOBACILLI AND LAC(-)PRT(-) LACTOCOCCI

Proteolysis and volatile components of semi-hard cheeses manufactured from a mixture of cow's,ewe's and goat's milk, with reduced fat conten t and concentrated by ultrafiltration, were followed during ripening. A starter culture (IFPL), consisting of several strains of Lactococcus , Lactobacillus and Leuconostoc, selected previously for its high prot eolytic activity, and the same starter with the addition of a concentr ate of Lactococcus lactis subsp lactis T1, lacking the ability to util ize lactose and casein (Lac(-)Prt(-)), were tested with the aim of acc elerating cheese ripening as compared with a commercial starter (FD). Casein hydrolysis was not affected by the type of starter culture empl oyed, whereas appreciable differences were found in the non-volatile w ater-soluble nitrogen fraction. The peptide pattern allowed a clear di stinction among cheeses made with different bacterial cultures. IFPL c heeses exhibited, after 1 month of ripening, a higher content of total free amino acids than FD cheeses after 3 months of ripening. Furtherm ore, the addition of L lactis T1 to the IFPL culture noticeably increa sed the release of total free amino acids during ripening, as well as the content of total volatile compounds.