Aiming at the identification of the key bitter peptides in fermented foods, a new approach, coined “sensoproteomics” was developed and applied to fresh cheese samples differing in bitter taste intensity. By means of MPLC-fractionation of the water-soluble cheese extracts in combination with taste dilution analysis, complex fractions with intense bitter taste were located and, then, screened by UPLC-MS/MS for the entire repertoire of ~1600 candidate peptides, extracted from a literature meta-analysis on dairy products, by using a total of 120 selected reaction monitoring (SRM) methods computed in silico. A total of 340 out of the 1,600 peptides were found in the cheese samples, amongst which 17 peptides were identified as candidate bitter peptides by considering only peptides that were located in the bitter tasting MPLC fractions (signal to noise ratio: ≥ 10) with a fold-change of ≥ 3 when comparing the less bitter to the more bitter cheese sample, and that were validated by comparison with the synthetic reference peptides. While EIVPNS[phos]VEQK (αs1-CN70-78) and INTIASGEPT (κ–CN122-131) did not exhibit any bitter taste up to 2,000 µmol/L, 15 of the 17 target peptides showed bitter taste thresholds ranging from 30 (ARHPHPHLSFM, κ-CN96-106) to 690 µmol/L (IQKEDVPS, αs1-CN81-88). Finally, quantitative peptide analysis, followed by calculation of dose-over-threshold factors revealed a primary contribution of MAPKHKEMPFPKYPVEPF (β–CN102-119) and ARHPHPHLSFM (κ-CN96-106) to the perceived bitter taste of the fresh cheese samples. Finally, the evolution of the bitter peptides throughout two different fresh cheese manufacturing processes were quantitatively recorded.     «

Aiming at the identification of the key bitter peptides in fermented foods, a new approach, coined “sensoproteomics” was developed and applied to fresh cheese samples differing in bitter taste intensity. By means of MPLC-fractionation of the water-soluble cheese extracts in combination with taste dilution analysis, complex fractions with intense bitter taste were located and, then, screened by UPLC-MS/MS for the entire repertoire of ~1600 candidate peptides, extracted from a literature meta-anal...     »