Dairy Industry Association of Australia

The delivery of calcium-alginate encapsulated peptidase, Flavourzyme from Aspergillus oryzae to enhance the proteolytic maturity of cheddar cheese was investigated. Cheeses with and without encapsulated enzymes were prepared and stored at 9°C for assessment of proteolytic maturity during ripening (0, 1 and 10 weeks). SDS-PAGE analysis of water-insoluble fractions clearly demonstrated that hydrolysis of casein after three months of
maturity was significantly increased in the experimental cheese, in particular, α and κ casein (CN) were largely degraded. The water-soluble fractions were subjected to RP-HPLC on C18 column for analysis of peptide profile. A large number of low molecular weight peptides were identified in experimental cheeses compared to the control cheese, and some of the peptides were unique to the experimental cheese and accumulated during ripening. Six of the identified peptides were purified on the same column using a binary gradient. N-terminal amino acid sequence analysis of identified new peptides were (P1:Leu-Thr-Glu; P3:Asp-Val-Pro-Ser-Glu) and relatively abundant stable peptides (P2, P4: Arg-Pro-Lys-His-Pro-Ile; P5:Arg-Pro-Lys-His-Pro-Ile-Lys and P6) and they mainly originated from αs1-CN and β-CN. Three of the identified peptides (P1, P2, P3 and P4) are known to be biologically active, and P1 and P3 were only present in the experimental cheese, suggesting that the encapsulated fungal peptidase derived from Aspergillus oryzae not only accelerated cheese ripening but has the potential to enrich the bioactive peptide profile in cheddar cheese.