Molecular mechanism underlying the effects of multisensory flavor perception on food palatability

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H03031
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Eating habits
• Research Institution: Tokyo University of Agriculture
• Principal Investigator: MAEHASHI Kenji 東京農業大学, 応用生物科学部, 教授 (20328545)
• Co-Investigator(Kenkyū-buntansha): 久保田 紀久枝 東京農業大学, その他部局等, 教授 (90008730)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 苦味受容体 / 甘味受容体 / うま味受容体 / 苦味抑制 / 茶カテキン / α-エチルグルコシド

Outline of Final Research Achievements

We investigated the effect of odorants on the bitter taste of catechins and sweet-bitter taste of ethyl α-D-glucoside (α-EG). We observed that the threshold levels of cardamom flavor fraction (CFF) significantly suppressed the bitterness of green tea by human sensory evaluation. Additionally, we confirmed the bitterness-suppression effect of CFF against epigallocatechin gallate (EGCg) via a cell-based assay using human bitter receptor (hT2R14)-expressing cells. Furthermore, more significant suppression of EGCg bitterness was observed when the hT2R14-expressing cells were prerinsed with CFF. It has been established that α-EG contributes to the unique flavor of sake, which tastes sweet with a bitter aftertaste. We found that both bitter and sweet receptor-expressing cells responded to α-EG. Our results indicate that α-EG activates not only sweet but also bitter receptors to elicit both sweet and bitter tastes, respectively.

Free Research Field

調味食品学

Academic Significance and Societal Importance of the Research Achievements

緑茶に多く含まれるエピガロカテキンガレート（EGCg)は多くの生理機能が知られており特定保健用食品の有効成分として広く利用されているが、その苦渋味によって嗜好性を損なうことが課題となっている。本研究でEGCgの苦味抑制においてカルダモン香気成分の有効性が認められたことは、香りによって味を改良できた例の一つとして食品産業に与えるインパクトは大きい。さらに香りによる味の改良が味覚受容体レベルでの作用である可能性を示す結果が得られたことは、味と香りの複合感覚によるおいしさ向上の分子機構解明の大きな手掛かりとして意義深い。