ISOLATION OF LOW-MOLECULAR-WEIGHT TASTE PEPTIDES FROM VACHERIN-MONT-DOR CHEESE

Vacherin cheese samples were extracted with water and the extracts fractionated by ultrafiltration excluding compounds with a molecular weight less than 1,000. Extract aliquots were fractionated by ligand exchange chromatography on a Sephadex derivative containing N-(2-pyridylmethyl)glycine-groups in Cu2+ form, permitting a specific group separation of peptides. Five peptide sub-groups were then chromatographed on Aminex A6 and Durrum DC 4 resin. Nine fractions from these separations were characterized by manual gas-phase isothiocyanate degradation and HPLC of the amino acid derivatives. Seven peptides could be identified: H-Leu-Pro-OH, H-Val-Pro-OH, H-Phe-Pro-OH, H-Lys-Pro-OH, H-Gly-Pro-Val-Arg-OH, H-Tyr-Pro-OH, and H-Arg-Pro-OH. A partial elucidation of the structure was possible for peptides containing Asp/Pro/Val/Leu, Glu/Leu, and Ala/Pro.