PROTEOLYSIS AND FLAVOR DEVELOPMENT IN LOW-FAT AND WHOLE MILK COLBY AND CHEDDAR-TYPE CHEESES (PEPTIDE PROFILES).

摘要

Colby like cheeses were used as a model examined to determine the effect lactic culture type, and fat contents on proteolysis, peptide patterns and development of flavor. The effects of ripening temperature were also investigated to determine the effects on flavor but not proteolysis. It was shown that culture type, ripening temperature, salt levels and fat levels influenced flavor profiles whereas only culture type, and salt content influenced proteolysis and peptide patterns. Off-flavors were noted more frequently in cheeses ripened at 10(DEGREES)C than those ripened at 4(DEGREES)C. Proteolysis and peptide patterns did not differ between cheeses of varying fat contents but flavor intensity was lower and off-flavors were more prevalent and intense in low-fat cheese. Through free energy of transfer equation it was shown off flavor compounds, especially bitter compounds, are likely to adsorb on the surface of the fat. This adsorption lowers the concentration of these compounds in the water phase of cheese, thus reducing their response level.;Cheddar cheeses were examined to determine the influence of enzyme modified cream (EMC), a neutral bacterial proteinase, fat level, and ripening temperature on development of flavor and influence on proteolysis. In whole milk Cheddar cheeses, Cheddar flavor intensity was accelerated by the use of the proteinase and ripening temperature but not by EMC treatments, suggesting that proteolysis is a rate limiting step in the production of Cheddar flavor. Cheddar flavor intensities equivalent to a 2 year old Cheddar were noted in the high enzyme cheeses ripened at 10(DEGREES)C. No typical Cheddar flavor development occurred in low-fat cheeses regardless of treatment, indicating that fat played a role in flavor development. This hypothesis was supported by electrophoretic patterns being equivalent between low-fat and whole milk cheeses from the various enzyme treatments. Similarities between flavor development and (gamma) casein patterns but not (alpha)(,s), (beta) or (alpha)(,s),-I casein patterns indicate that peptides may be involved with flavor development more than the primary products of proteolysis.