Hydrophilic di- and tripeptides are not a precondition for savoury flavour in mature Cheddar cheese

In the literature hydrophilic glutamyl di- and tripeptides have been described to induce an umami or savoury taste. In this study, HILIC-ESI-MS was applied for analysis of low-molecular-weight peptides in the ultra-filtrated (cut-off 10 kg.mol(-1)) water-soluble extract of two mature Cheddar cheeses, selected because of their pronounced savoury flavour. A reference mixture of amino acids and di- and tripeptides was successfully separated by HILIC using ammonium acetate buffer (0.50 g.L-1, pH 5.5) as the mobile phase. Unambiguous identification of the compounds was based on retention time and characteristic fragmentation patterns in MS/MS and MS3. However, no low-molecular-weight glutamyl peptides were identified in the extracts of the mature Cheddar cheeses. It was concluded that hydrophilic glutamyl di- and tripeptides are not a precondition for savoury flavour in mature Cheddar cheese.