Transformation of tea catechins and flavonoid glycosides by treatment with Japanese post-fermented tea acetone powder
- 作者：Takashi Tanaka ; t-tanaka@nagasaki-u.ac.jp ; Hirotaka Umeki ; Sachi Nagai ; Takuya Shii ; Yosuke Matsuo ; Isao Kouno
- 关键词：Post-fermented tea ; Anaerobic fermentation ; Acetone powder ; Catechin metabolites ; Polyphenol
- 刊名：Food Chemistry
- 出版年：2012
- 期刊代码：48_03088146
- 类别：abs
- 出版时间：1 September, 2012
- 卷：134
- 期：1
- 页码：276-281
- 文件大小：438 K
摘要
Japanese post-fermented teas are produced by a combination of aerobic and anaerobic microbial fermentation of the leaves of tea plant. Recently, it was revealed that tea products contain characteristic polyphenols identical to the tea catechin metabolites produced by mammalian intestinal bacteria, such as (2S)-1-(3鈥?4鈥?5鈥?trihydroxyphenyl)-3-(2鈥?4鈥?6鈥?trihydroxyphenyl)-propan-2-ol (EGC-M1). In the present study, degradation of epigallocatechin-3-O-gallate (EGCg) and epigallocatechin (EGC) with acetone powder prepared from Japanese post-fermented tea was examined. Under aerobic conditions, EGCg was hydrolysed to EGC and gallic acid, which were further converted to gallocatechin (GC) and pyrogallol, respectively. Under anaerobic conditions, EGCg was hydrolysed to EGC, which was further metabolised to GC, EGC-M1 and (4R)-5-(3,4,5-trihydroxyphenyl)-4-hydroxypentanoic acid (EGC-M2). Gallic acid was degraded to pyrogallol and then further decomposed. Anaerobic treatment of EGC with the acetone powder yielded EGC-M1, EGC-M2, (4R)-5-(3,4,5-trihydroxyphenyl)-纬-valerolactone, and (4R)-5-(3,4 -dihydroxyphenyl)-纬-valerolactone. Furthermore, similar anaerobic treatment of rutin and hesperidin yielded 3,4-dihydroxyphenylacetic acid and 3-(3,4-dihydroxyphenyl)propanoic acid, respectively.