Abstract
A systematic study identified umami peptides in lager beer, probed T1R1/T1R3 mechanisms, and quantified multidimensional sensory effects. RPLC-Q-TOF-MS with database search and de novo sequencing identified 1178 peptides; UMPred-FRL and TastePeptides-Meta yielded 142 candidates, of which 128 docked to modeled T1R1/T1R3. Four peptides-EESY, IEVVD, EIVDV, IGVND-were advanced to MD/MM-GBSA and sensory tests. Complexes showed favorable gas-phase interactions offset by polar solvation; binding free energies (kcal/Mol, mean ± SD) were EESY -70.91 ± 7.37, EIVDV -61.26 ± 3.42, IEVVD -60.93 ± 2.33, IGVND -55.24 ± 3.69, indicating EESY had the highest affinity/stability. Single-addition tests increased "umami" by +41.5 % (EESY), +34.0 % (IGVND), +14.9 % (IEVVD), and + 1.1 % (EIVDV). Effects concentrated in taste: EESY and IGVND reduced bitterness and enhanced overall balance; EIVDV maximized balance (+18.11 %) with slight bitterness rise; IEVVD increased bitterness (+17.65 %) yet improved balance. This established an integrated workflow for formulation optimization of lager beer.