Nitrogen dioxide removal activity of tannin polymers from barks

Research Project

Project/Area Number	18K05771
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 40020:Wood science-related
Research Institution	Forest Research and Management Organization
Principal Investigator	Makino Rei 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員等 (50353850)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000) Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2018: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywords	タンニン / 二酸化窒素 / 樹皮 / 抗酸化能
Outline of Final Research Achievements	The purpose of this study was to elucidate the antioxidative activity of condensed tannins from barks in vapor phase. We evaluated the antioxidative activity in vapor phase by nitrogen dioxide (NO2) removal activity, an air pollutant with strong oxidative properties. The relationship between structural changes in tannins by steam-explosion treatment and NO2 removal activity was investigated. As a result, the NO2 removal activity of tannin polymers increased by steam-explosion treatment regardless of their unit structures. It was found that steam-explosion treatment is the effective method to improve the NO2 removal activity of tannins.
Academic Significance and Societal Importance of the Research Achievements	タンニンとその代表的な構成単位である単量体のカテキンは、多くの有用機能で同等の活性を示し、重合物であるタンニンの機能の優位性は明らかではないことが多い。本研究は、樹皮に多く含有するタンニンが、気相で特徴的に持つ新たな有用機能について、重合物である化学特性と機能との関係を明らかにした。また、蒸煮爆砕処理を用いて、特殊な触媒や有機溶剤を用いることなく、水のみで重合物であるタンニンの化学変換を行い、二酸化窒素除去能を向上させることができた。本成果は、樹皮の高付加価値利用への貢献が期待される。