Methods for Assessing Proteolysis in Cheese During Maturation

Proteolysis in Teleme cheese made from ewes’, goats’ or a mixture of ewes’ and goats’ milk

“…Low molecular mass peptides (o600 Da) and amino acids (except lysine and arginine) present in cheese are soluble in 5% PTA (Jarrett, Aston, & Dulley, 1982). Most of these compounds are produced by the action of peptidases from the starter culture (Visser, 1977;Fox et al, 1995a). The type of milk employed did not result in any significant (P>0.05) differences in the levels of PTA-N values (Table 1).…”

“…One of the major biochemical changes during cheese ripening is proteolysis (Fox, McSweeney, & Singh, 1995a;McSweeney & Sousa, 2000), which directly affects the development of the desired texture, aroma, and intensity of background flavor of most mature cheeses (Fox, Singh, & McSweeney, 1995b). The breakdown of the protein network plays an essential role in the development of textural properties and in the release of free amino acids.…”

Volatile organic compounds of a Swiss cheese slurry system with and without added reduced glutathione, compared with commercial Swiss cheese

“…The H/S concentration in both the GSH slurry system and Swiss cheese samples from the different stages of manufacture remained constant during ripening. 2-Methylpropanal is produced via amino acid catabolism through a Strecker degradation reaction of valine, so apparently GSH inhibits this reaction, similar to what occurs during cheese ripening (Fox, McSweeney, & Singh, 1995;McSweeney & Sousa, 2000).…”

Application of proteomic techniques to protein and peptide profiling of Teleme cheese made from different types of milk

“…A potential solution is to include an appropriate pre-fractionation of cheese proteins and peptides prior to proteomic analysis. The water-soluble fraction of cheeses is known to contain a spectrum of proteolysis products ranging from proteins, but excluding caseins, and peptides to amino acids and smaller N compounds such as amines, urea and ammonia (Fox, McSweeney, & Singh, 1995). This fraction of cheese, known to contain the components that make a major contribution to flavour (Salles, Septier, Roudot-Algaron, Guillot, & Etievant, 1995) is widely used to produce an index of cheese ripening and to isolate peptides and amino acids (Fox et al, 1995).…”