Definition, Objectification and Globalization of "Koku" Based on Scientific Data

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K12710
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Eating habits
• Research Institution: Kagawa Nutrition University (2017-2019); Nippon Veterinary and Life Science University (2016)
• Principal Investigator: Nishimura Toshihide 女子栄養大学, 栄養学部, 教授 (70180643)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: コク / 複雑さ / 広がり / 持続性 / とろみ / 増粘剤 / 口中香 / 国際化

Outline of Final Research Achievements

Koku was defined to be one of the objective factors as well as taste, aroma and texture, and to be composed of basic attributes such as complexity, mouthfulness and lingeringness (continuity). The complexity in Koku attributes of foods has been shown to be formed in the processing of heating, aging or fermentation in which lots of taste compounds and aroma compounds were produced. Their strengths are dependent on the time in these processings. The mouthfulness or lingeringness in Koku attributes of foods is clarified to be enhanced by the presence of umami compounds, lipids and/or viscosity in liquid foods. The popularization of Koku in Japan was started by symposium in "the Koku meeting", and the globalization of koku are carried on by the international symposium and the publication of the book titled “Koku in Food Science and Physiology”.

Free Research Field

食品栄養学、食品科学

Academic Significance and Societal Importance of the Research Achievements

コクは、おいしさの同義語として使用されてきたが、本研究で、味や香りと同様、おいしさを決める客観的要因として、明確に定義された。また、中華スープやソーセージで、それぞれのコクを「複雑さ」、「広がり」、「持続性」の要素の強弱で表せることを示した。さらに、低粘度溶液で感じられる「とろみ」が、コクの持続性に寄与していることも明らかにできた。これらの成果は、新規性が高く、学術的意義が大きい。コクの定義と見える化は、コク研究会主催シンポジウムを通して広く社会に発信されているので、食品表示にわかりやすく表示されると期待できる。国際シンポジウムの開催と英文書籍の出版を通した世界への波及効果も期待される。