Seven novel umami peptides from Takifugu rubripes and their taste characteristics

•Seven novel umami peptides were found in Takifugu rubripes.•The C-terminal basic amino acids contribute to the umami attributes of peptide.•Nano-LC/Q-TOF-MS was the firstly used in the identification of taste peptide.•Actin as one of important taste-active precursors was found in Takifugu rubripes. Pufferfish is worldwide known for its umami taste. Previous studies showed that umami peptide played a key role in taste perception of pufferfish. In order to more explain the umami taste of pufferfish in details, this study was aimed to identify more umami peptides from pufferfish. The extraction of Takifugu rubripes (T. rubripes) muscle after heating and ultrasound treatment was isolated by consecutive chromatography combined with sensory evaluation. The results showed that seven umami peptides from 300 to 3000 Da molecular weight range fractions were firstly identified by nano-liquid chromatography quadrupole time of flight mass spectrometry (Nano-LC/Q-TOF-MS), and peptide sequences are HLQLAIR, DPLRGGYY, AGLQFPVGR, LLLPGELAK, AGFAGDDAPR, GYSFTTTAER and DAGVIAGLNVLR. The taste characteristics of seven peptides were analyzed based on sensory evaluation, and their umami thresholds were in the ranges of 0.06–0.27 mM. Peptide sequences source analysis found that actin was one important taste-active precursor of the umami peptides in T. rubripes.