Analysis of BSA-non-precipitable tannin in red wine and its possible role on palatability

• Project/Area Number: 17K07812
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Food science
• Research Institution: University of Yamanashi
• Principal Investigator: Tohru OKUDA 山梨大学, 大学院総合研究部, 教授 (10252008)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: ワイン / ポリフェノール / タンニン / 渋味 / ブドウ / おいしさ

Outline of Final Research Achievements

Tannin is a one of the most important polyphenols in red wine because it evoke astringency sensation. This sensation is known to cause by the formation of insoluble complex with tannin and proteins in saliva. Using this unique character of tannin, a method was developed to measure the concentration of tannin in wine. In this method, bovine serum albumin (BSA) is added as protein to wine and measuring precipitated tannins. We firstly found that there were many tannins that has poor precipitate ability with BSA in red wine. The exsistence of this unprecipitable tannin with protein may have no astringent sensation, and will affect the taste of red wines.

Academic Significance and Societal Importance of the Research Achievements

本研究では，タンパク質を添加しても沈殿を生じないワインタンニンの存在を明らかにした。このようなタンニンは渋みを持たないと思われる。一般に赤ワインは肉やチーズなど，タンパク質を豊富に含む食品との相性が良いとされている。赤ワインの口中での反応はよくわかっていないが，本研究はワインの食べ合わせや，品質にも直結する重要な発見である。タンパク質である牛血清アルブミンの添加によって沈殿しないBSA非沈殿性タンニンは，BSA沈殿性タンニンと同程度の濃度存在した。また，醸造試験の結果，BSA非沈殿性タンニンは醸造初期から存在し，ブドウ中に既に存在することも考えられた。

Research Products

• [Presentation] 日本ワイン中のBSA非沈殿性タンニンの定量 (2019)
  • Author(s): 猪狩太基，渡辺（斉藤）史恵，久本雅嗣，奥田 徹
  • Organizer: 日本ブドウ・ワイン学会
• [Presentation] Concentrations of BSA-precipitable and BSA-non-precipitable tannins in Japanese wines (2019)
  • Author(s): Tohru OKUDA, Taiki IGARI, Eri INOUE, Fumie SAITO-WATANABE, Masashi HISAMOTO
  • Organizer: Am. Soc. Enol. Vitic.
• [Presentation] Adsorption potential of grape insoluble polysaccharides to red wine phenolics (2018)
  • Author(s): Eri Inoue, Haruka Kobayashi, Riku Hoshino, Fumie Saito, Masashi Hisamoto, and Tohru Okuda
  • Organizer: American Society for Enology and Viticulture
  • Int'l Joint Research
• [Presentation] Understanding composition of white wine lees during vinification (2018)
  • Author(s): Tohru OKUDA, Guangxian LIANG, Masaru GOZU, Fumie SAITO-WATANABE, Masashi HISAMOTO
  • Organizer: American Society for Enology and Viticulture
  • Int'l Joint Research