Generation and identification of kokumi compounds and their validation by taste-receptor assay: An example with dry-cured lamb meat

Kokumi tastants are small gamma-glutamyl peptides (GGP) that enhance flavour in foods. We sought to generate GGP from the meat crusts of dry-cured lamb, an underutilised protein resource, identify these using mass spectrometry, and validate their functional activity using a kokumi-calcium sensing receptor (CaSR) assay. The water-soluble extract (WSE) of meat crust was hydrolysed by protease A (PA) and treated with glutaminase (GA). Fifteen GGP were identified, with 14 being significantly increased in PA and GA groups compared to WSE, as were along with free amino acid levels. The GA extract activated CaSR with higher potency and efficacy than PA and WSE suggesting the generation of potent kokumi tastants. The in vitro receptor assay might be an expedient tool for screening kokumi tastants prior to conducting human sensory analysis. Collectively, our findings indicate that the meat crust can be a valuable source to generate kokumi tastants via a two-step enzymatic reaction.

Automated summary

This study successfully identified gamma-glutamyl peptides (GGP) from the meat crusts of dry-cured lamb, which can enhance the flavor in foods. The results showed that glutaminase (GA) extract exhibited higher potency and efficacy in activating the kokumi-calcium sensing receptor (CaSR) compared to protease A (PA) and water-soluble extract (WSE). The in vitro receptor assay could be a convenient tool for screening kokumi tastants.