Abstract:Umami is one of five basic tastes, which has been playing an increasingly important role in the selection of food products. Peptides are primary tastants composed of amino acids with several tastes. Peptides with significant umami taste could be produced through proteolysis. An umami peptide was isolated and purified from wheat gluten fermentation broth by ultra-filtration (UF), gel filtration chromatography (GPC), reverse phase high-performance liquid chromatography (RP-HPLC), and sensory evaluation. The sequence and molecular weight of the umami peptide were identified by matrix-assisted laser desorption/ionization- time-of-flight - mass spectrometry (MALDI-TOF-MS). The identified peptide was synthesized and taste dilution analysis (TDA) was conducted to evaluate taste characteristics of the peptide. The umami peptide was identified to be Asp-Cys-Gly (DCG) and the molecular weight was 293.15 Da. TDA results showed that the umami taste threshold of the peptide was 100 mg/mL, which was one third of MSG. DCG can enhance the umami taste of I+G at a concentration of 200 mg/L, but no similar effect was found with MSG.
