全粒大豆と脱脂大豆の新規うま味活性ペプチドの比較研究

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

• Xiping Zhu
• Dongxiao Sun-Waterhouse
• Jiahui Chen
• Chun Cui
• Wei Wang

抄録

背景:

大豆を丸ごと発酵させて製造した2種類の醤油（それぞれSSS、SSDと呼ぶ）を高濃度エタノール水溶液で処理した後、マクロポーラス樹脂とRP-HPLCを用いて官能誘導分画を行い、UPLC-Q-TOF MS/MSで抽出した。その後、マクロポーラス樹脂とRP-HPLCを用いた官能誘導分画によりSSSとSSDからおいしいペプチドを分離し、UPLC-Q-TOF MS/MSにより同定した。

BACKGROUND: Two kinds of soy sauce produced via fermentation of the whole soybeans and the defatted soybeans (soy sauce termed 'SSS' and 'SSD', respectively) were subjected to the treatment using aqueous ethanol solutions with high concentrations. Then tasty peptides were separated from SSS and SSD by sensory guided fractionation, using macroporous resin and RP-HPLC, and identified by UPLC-Q-TOF MS/MS.

結果:

その結果、うま味活性画分と≤ 3 kDaのペプチドは、主に60%エタノールで処理した上清に濃縮され、沈殿物は80%エタノールで処理した結果であることが示された。アンモニア性窒素、非塩分固形分、苦味のあるアミノ酸、ペプチド中のアミノ酸の含有量、および≦3 kDaペプチドの割合は、SSSの方がSSDよりも高かった。SSSSとSSDからは16種類と14種類の旨味ペプチドが分離されたが、その中でグルタミン酸残基を有する5種類のジペプチド(γ-Glu-Glu, Glu-Glu, γ-Glu-Cys, γ-Glu-Leu, Glu-Leu, Ile-Glu)がSSSとSSDの両方で同定され、醤油中のうま味・コク味活性ペプチドとして報告されている。また、SSS（Thr-Gly-Cys, Gly-Leu-Glu, Val-Glu-Ala-Leu, Gly-Gly-Glu）およびSSD（Asp-Arg, Asp-Ala-Glu, Glu-Val-Cys, Gly-Gly-Gly-Glu）から同定されたペプチドは、旨味・うま味活性ペプチドとして報告されているが、これまで旨味・コク味活性ペプチドとして報告されていなかったものであった。

RESULTS: The result showed that umami-active fractions and ≤ 3 kDa peptides were mainly concentrated in the supernatants resulted from the treatment with 60% ethanol and the precipitates resulted from the treatment with 80% ethanol. The contents of ammonia nitrogen, non-salt solids, bitter amino acids, amino acids in peptides and the proportion of ≤3 kDa peptides in SSS were higher than those in SSD. Sixteen and fourteen tasty peptides were separated from SSS and SSD, among them five dipeptides (γ-Glu-Glu, Glu-Glu, γ-Glu-Cys, γ-Glu-Leu, Glu-Leu and Ile-Glu) with a glutamic acid residue were identified both in SSS and SSD, which have been reported as umami/kokumi-active peptides in soy sauce. Several peptide identified from SSS (Thr-Gly-Cys, Gly-Leu-Glu, Val-Glu-Ala-Leu and Gly-Gly-Gly-Glu) and SSD (Asp-Arg, Asp-Ala-Glu, Glu-Val-Cys and Gly-Gly-Gly-Glu) are tasty and/or umami-active peptides but have not been reported as tasty peptides in the past.

結論:

SSDとSSSから分離されたペプチドのほとんどが醤油のうま味増強効果を付与することができ、SSDよりもSSSの方がコクミと苦味の疎水性ペプチドがわずかに多く見られた。この記事は著作権で保護されています。無断転載を禁じます。

CONCLUSION: Most of peptides separated from SSD and SSS could impart an umami-enhancing effect on soy sauce, and the marginally more kokumi and bitterness hydrophobic peptides were found in SSS than SSD. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.