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

Abstract

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.

Decoding of the Saltiness Enhancement Taste Peptides from the Yeast Extract and Molecular Docking to the Taste Receptor T1R1/T1R3

“…are the most widely used to reduce the sodium intake, but they can introduce an unpleasant taste. − Optimization of the shape and particle size of salt crystals, the inhomogeneous distribution of salt in food matrices, or even restructuring food matrices to enhance the saltiness perception are the effective strategies for addressing the unpleasant taste. − The cross-modal interaction between taste and aroma perception also enhances the taste perception through multisensory synergy . For example, several key odorants from soy sauce and dried shiitake mushroom aqueous extracts reduce the addition of salt to meat products without affecting the saltiness intensity. , Additionally, commercial taste enhancers [such as monosodium glutamate, yeast extracts (YE), amino acids, nucleotides, low-concentration organic acids, and taste-improving peptides] play an important role in enhancing the saltiness. − …”

“…23 The taste peptide EDEGEQPRPF isolated from a commercial plain fermented soybean curd was also reported to have saltiness-enhancing effects. 21 The peptides in the YE sample were statistically summarized, currently, 30 taste peptides contributing to umami and saltiness perception. Moreover, YE could inhibit off-flavors and achieve the salt reduction without decreasing the saltiness intensity.…”

Reduction of sodium chloride: a review

“…86 Chen et al isolated saltinessenhancing peptides EDEGEQPRPF from Chinese commercial fermented soybean curds; they could be a possible alternative to partially reduce the amount of sodium intake without compromising saltiness. 87 Saltiness enhancing peptide can not only increase the saltiness of food without adding additional sodium ions but can also increase the nutritional value of food to a certain extent. However, there has been relatively little research on this or its mechanism.…”

Pseudo-Taste Cells Derived from Rat Taste and Non-Taste Tissues: Implications for Cultured Taste Cell-Based Biosensors

“…14−16 While some of them used the cultured taste cells to screen taste-active compounds or study the taste signaling pathways, 8,14−16 the identities and functional characteristics of the taste cells in vitro have never been carefully scrutinized. 15 To date, it is still undetermined to what extent the so-called "cultured taste cells" recapitulate the taste cells in vivo.…”

“…In particular, there is still insufficient knowledge on the growth characteristics of taste cells in vitro . For example, although taste cells in vivo exhibit spindle morphology, significant morphological differences were observed between cultured human, rat, and porcine taste cells. − Some of the cultured taste cells in the previous literature displayed epithelial-like morphology, whereas others assumed fibroblast-like shapes. − Moreover, cultured taste cells seemed to display morphological changes over time, although the reasons have remained unclarified. , So far, the application of cultured taste cells in taste research is only limited to several research groups. − While some of them used the cultured taste cells to screen taste-active compounds or study the taste signaling pathways, ,− the identities and functional characteristics of the taste cells in vitro have never been carefully scrutinized . To date, it is still undetermined to what extent the so-called “cultured taste cells” recapitulate the taste cells in vivo .…”