Isolation and Identification of Low-Molecular-Weight Peptides from Emmentaler Cheese

ABSTRACT: Four peptides, derived from the N-terminal fragment of α_sl -casein CN (1–9), CN (1–12), CN (1–13) and CN (1–14)] were isolated from a low-molecular-weight extract of a commercial Emmentaler cheese (age: approx. 5.5 mo) by gel filtration and RP-FPLC. Capillary zone electrophoresis was used to check the purity of the peptides. Using automatic Edman degradation and MALDI-TOF mass spectrometry, amino acid sequence and molecular mass of the peptides were determined to identify them. The peptide α_sl -CN (1–13) was identified for the first time in Emmentaler cheese. The peptide fraction was shown not to contribute to the characteristic flavor of Emmentaler cheese.