Chemical mechanism underlying internal blue discoloration of daikon roots and suppression of the discoloration onset

• Project/Area Number: 16K14852
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Horticultural science
• Research Institution: Mie University
• Principal Investigator: TERANISHI KATSUNORI 三重大学, 生物資源学研究科, 教授 (20237001)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 青変症 / ダイコン / 生理現象 / 野菜 / 天然物化学 / 青色色素 / 植物生理障害

Outline of Final Research Achievements

Internal blue discoloration is observed in daikon roots on a few days after harvest and poses a significant problem to farmers in recent years. To circumvent the blue discoloration, we studied on the chemical mechanisms underlying the discoloration and methods for the suppression of the discoloration onset. We discovered that 4-hydroxyglucobrassicin is only precursor to the blue components in daikon roots and immediately offers blue components by oxidation reaction under the extreme oxidative stress. Moreover, it was clarified that cultivation conditions influence the amounts of 4-hydroxyglucobrassicin, anti-oxidative compounds, which reduce the oxidative stress.