Chemical change of tea polyphenol in the production process of black tea and roasted green tea
| Project/Area Number |
25870532
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Eating habits
Food science
|
|---|
| Research Institution | Nagasaki University |
|---|
Principal Investigator |
MATSUO Yosuke 長崎大学, 医歯薬学総合研究科(薬学系), 助教 (10432981)
|
|---|
| Project Period (FY) |
2013-04-01 – 2015-03-31
|
| Project Status |
Completed (Fiscal Year 2014)
|
| Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2013: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
|
|---|
| Keywords | ポリフェノール / 紅茶 / ほうじ茶 / エピガロカテキン / テアフラビン / DFT / ECD / DFT計算 |
|---|
| Outline of Final Research Achievements |
Enzymatic oxidation of theaflavins in the presence of epicatechin was examined. Benzotropolone moiety of theaflavins with a free hydroxyl group at C-3' easily reacted with epicatechin; however, benzotropolone moiety of theaflavins having galloyl group at C-3' could not react with epicatechin. The charge-transfer interaction between benzotropolone ring and o-quinone ring of epicatechin-quinone is important in benzotropolone oxidation.
The structure of a new enzymatic oxidation product of epigallocatechin was determined. In addition, we assigned the stereostructure of known oxidation products of pyrogallol-type catechins, such as quinone dimers, theacitrins, and proepitheaflagallins, by using theoretical calculations of ECD spectra and NMR chemical shifts.
In the course of roasted green tea production, high molecular weight polyphenols are produced. We found that they are generated by condensation reaction between tea catechins and caramelized sugars.
|
Report
(3 results)
Research Products
(23 results)
