CONTRIBUTION OF STARTER AND ADJUNCT LACTOBACILLI TO PROTEOLYSIS IN CHEDDAR CHEESE DURING RIPENING

摘要

Proteolysis in Cheddar cheese made with or without adjunct lactobacilli and acidified with starter or glucono-delta-lactone (GDL) was monitored during ripening. The pH of the GDL cheeses was higher than that of the starter cheeses, resulting in lower chymosin activity in the former which was apparent in electrophoretograms of the cheeses throughout ripening. Although the coagulant appeared to be responsible for most of the water-soluble N (WSN), the starter also contributed, as shown by differences between electrophoretograms of the WSN extracts of the starter and GDL cheeses. The starter enzymes were the major contributors to the production of small peptides and free amino acids. Addition of adjunct lactobacilli to the starter-free cheeses caused a significant increase in proteolysis. This increase in proteolysis was not as apparent when the adjunct lactobacilli were added to the starter cheese, possibly due to the lack of available substrate for the wide range of enzymes supplied by both the starter lactococci and adjunct lactobacilli.