Hydrolysis of muscle myofibrillar proteins by Lactobacillus curvatus and Lactobacillus sake

Proteolytic enzyme activities of whole cells and cell free extracts (CFE) of Lactobacillus curvatus CECT 904 and Lactobacillus sake CECT 4808 were characterised using synthetic chromogenic compounds and myofibrillar proteins as substrates. The hydrolytic action was monitored by SDS–PAGE and reverse phase-HPLC analyses. The CFE of L. sake partially contributed, together with muscle enzymes, to the initial hydrolysis of myofibrillar proteins. Whole-cells of both L. curvatus and L. sake generated peptides considered important for cured-meat taste. The peptide mapping, resulting from the action on the substrates assayed, revealed a profile of extra and intracellular enzymes. Both strains expressed strong amino acid metabolism.