Flavor Constituents of Aqueous Fraction Extracted from Comte Cheese by Liquid Carbon Dioxide

Abstract

ABSTRACT Isolation, purification and identification of some low‐molecular‐weight compounds from a water‐soluble extract of Comté cheese was achieved. We used liquid CO 2 extraction, subsequent fractionation (by gel permeation and reserve‐phase HPLC) and mass spectometry. Major constituents were N‐acyl amino acids (N‐acetyl methionine, N‐propionyl methionine, N‐propionyl leucine, N‐propionyl phenylalanine), dike‐topiperazines (cyclo(Pro‐Pro), cyclo(Pro‐Val), cyclo(Pro‐Phe), cy clo(Pro‐Leu), cyclo(Pro‐Ala)) and non‐peptide compounds (theo‐bromine, 4‐methyl‐t‐thiazoleethanol, uracil, (5–6)dihydro‐uracil, thymine). These compounds were synthesized and tasted. Most were bitter. N‐propionyl methionine had a cheese flavor but was not detected when added to a simulated cheese at 180 mg/L.