Bitter‐tasting hydrophobic peptides prepared from soy sauce using aqueous ethanol solutions influence taste sensation

Abstract

In this study, bitter-tasting hydrophobic peptides were prepared and purified from soy sauce using aqueous ethanol solutions and ion exchange resin, and analysed using RP-HPLC and UPLC-Q-TOF-MS/MS. Most of bitter fraction from soy sauce was obtained by treatments involving 80% ethanol and subsequent chromatographic separation. This fraction contained sixteen small peptides (molecular weight < 1000 Da; rich in hydrophobic amino acids with Lys-Pro (KP), Glu-Phe (EF), Glu-Val (EV), Asp-Leu (DL), Leu-Trp (LW) and Asp-Pro (DP)) capable of enhancing significantly (P < 0.05) umaminess and/or imparting kokumi effect in taste reconstitution experiments. Thus, the bitter peptides affected bitterness as well as other taste sensations like umaminess, kokuminess and saltiness. This was the first study to report the impacts of the bitter-tasting hydrophobic peptides on soy sauce and solutions of salt, monosodium L-glutamate.

Comparative study on the novel umami‐active peptides of the whole soybeans and the defatted soybeans fermented soy sauce

“…Based on the results of basic quality, it can be speculated that a part of the salt and sugar have been precipitated with aqueous ethanol solutions of increasing concentrations. Studies by Zhu et al 17 . showed that the fraction derived from soy sauce exhibited the strongest umami taste and greatest kokumi sensation.…”

“…60% and 80%) according to Zhu et al . method 17 . In detail, freeze‐dried SSS or SSD were firstly dissolved into 60% ethanol solution (final concentration: 30 mg solid mL –1 ), prior to mixing in a Water Bath Shaker 720 × g for 30 min and centrifugation at 4 °C and 8000 × g for 10 min.…”

“…The column was TSK gel G2000 SWXL metal column (Tosoh, Tokyo, Japan). The determination method is carried out according to Zhu et al 17 . and the detection wavelength was 220 nm.…”

“…Ethanol and aqueous ethanol solutions are commonly used media for extracting or precipitating polysaccharides, proteins and small molecules 15,16 . Zhu et al 17 . enriched the strongest umami taste fraction from soy sauce by concentrating the supernatants resulting from the treatment with 60% ethanol and the precipitates resulting from the treatment with 80% ethanol.…”

Enrichment of the umami‐taste‐active amino acids and peptides from crab sauce using ethanol precipitation and anion‐exchange resin

“…Resin is a strong separation method to purify proteins, peptide and amino acids because of its high speed and efficiency (Liu et al., 2020; Zhu et al., 2020; Zhuang et al., 2016). Anion‐exchange resin is widely used for the separation of compounds which carry a net negative charge, and it could be used to separate different proteins (Staby et al., 2000) and acidic peptides (Wilson et al., 2006).…”