Saltiness-Enhancing Peptides Isolated from the Chinese Commercial Fermented Soybean Curds with Potential Applications in Salt Reduction

• DOI: 10.1021/acs.jafc.1c03431
• Publication Date: 2021-08-26T19:11:16Z
• Authors: Yan Ping Chen; Mengni Wang; Imre Blank; Jiaojiao Xu; Hau Yin Chung
• Keywords: 0301 basic medicine; 2. Zero hunger; China; 03 medical and health sciences; Tandem Mass Spectrometry; Taste; Animals; Soy Foods; Sodium Chloride; Peptides; Rats

Salt is very important for human health and food seasoning. Recently, several peptides isolated from natural food products have been reported exhibiting a salty taste or a saltiness-enhancing function. In this investigation, taste-active peptides occurring in commercial Chinese fermented soybean curd were isolated and identified using ultrafiltration, gel permeation chromatography, ion-exchange chromatography, and nano-LC/Q-TOF MS/MS. The salty taste-enhancing function of the target fractions was confirmed by both a rat taste cell model and/or human sensory evaluation. Four decapeptides were found as taste-active compounds. Among them, peptide E (EDEGEQPRPF) was the most potent saltiness-enhancing peptide: 0.4 mg/mL in 50 mmol/L NaCl solution could increase its salty perception equivalent to the salt level of 63 mmol/L NaCl reference solution. The sequence of the peptide has been found in the α'-subunit of β-conglycinin [Glycine max]. The remaining peptides V (VGPDDDEKSW), DD (DEDEQPRPIP), and DG (DEGEQPRPFP) showed umami and kokumi tastes as well as a weak saltiness-enhancing sensation. These findings suggest that the decapeptide EDEGEQPRPF could be a possible alternative to partially reduce the amount of sodium intake without compromising for saltiness.