Identification of novel saltiness-enhancing peptides from yeast extract and their mechanism of action for transmembrane channel-like 4 (TMC4) protein through experimental and integrated computational modeling.

Excessive consumption of sodium salt is one of the important inducers of cardiovascular and cerebrovascular diseases. The reduction of physical labor and attention to health make research on low-sodium salt imminent. Ultrafiltration, gel filtration, preparative high-performance liquid chromatography, and liquid chromatography with tandem mass spectrometry were employed for further purification and identification of the salty enhancing peptides in yeast extracts. Moreover, human transmembrane channel-like 4 (TMC4) was constructed and evaluated by computer-based methods, and salt-enhancing peptides were identified based on its allosteric sites. PN, NSE, NE and SPE were further determined to be salty enhancing peptides through sensory evaluation, and their taste mechanism was investigated. The results presented here suggest that silicon screening focused on TMC4 allosteric sites and sensory evaluation experiments can greatly increase the discoverability and identifiability of salty enhancer peptides, and this strategy is the first to be applied to the development of salty enhancer peptides.

Characterization of odor-active compounds in moso bamboo (Phyllostachys pubescens Mazel) leaf via gas chromatography-ion mobility spectrometry, one- and two-dimensional gas chromatography-olfactory-mass spectrometry, and electronic nose.

The leaf of moso bamboo (Phyllostachys pubescens Mazel) is rich in odorant compounds, which is important natural materials for the production of flavor. It also contains phenolic acids, amino acids and peptides, which is a potential source of natural bioactive compounds. The study of odor-active compounds in bamboo leaves can provide a basis for the discovery of natural flavor. The leaf, stem, and powder of moso bamboo were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS). Main odor-active compounds in moso bamboo leaf were analyzed and characterized by (1) a gas chromatography olfactory mass spectrometry (GC-O-MS), (2) two-dimensional gas chromatography olfactory mass spectrometry (GC × GC-O-MS) and (3) electronic nose (E-nose). Based on aroma extract dilution analysis (AEDA), 13 key odor-active compounds with high flavor dilution (FD) factor (≥27), including 3-methyl-1-butanol, (E)-2-hexenal, ethyl hexanoate, (Z)-4-heptenenal, 6-methyl-5-hepten-2-one, octanal, ethyl (Z)-3-hexenoate, 1-hexanol, (Z)-3-hexen-1-ol, (E, E)-2,4-heptadienal, (Z)-2-hexen-1-ol, 1-octen-3-ol and benzaldehyde, were further analyzed. The compounds detected by the above four methods were (E)-2-hexenal, 6-methyl-5-hepten-2-one, octanal, (E, E)-2,4-heptadienal, 1-octen-3-ol and benzaldehyde, and all of which were the main and potential odorants of moso bamboo leaf.