J. Technology and Education, Vol.25, No.2, pp.37-45 (2018)

研究論文

香煎茶のポリフェノール成分における抗酸化作用

 

芳野恭士*¹、杉本奈央¹、塩川阿子香¹、芳野広起¹、後藤健太¹、清水　篤²

¹沼津工業高等専門学校　物質工学科（〒410-8501　沼津市大岡3600）

²サンダイヤ株式会社（〒103‐0007　東京都中央区日本橋浜町1-1-12）

*k-yoshino@numazu-ct.ac.jp

 

Antioxidant Activity of Polyphenolic Components in Kosencha

 

Kyoji YOSHINO¹, Nao SUGIMOTO¹, Asuka SHIOKAWA¹, Hiroki YOSHINO¹,

Kenta GOTO¹, Atsushi SHIMIZU²

¹Numazu College of Technology (3600 Ooka, Numazu, Shizuoka 410-8501, Japan)

² Sundia Co., Ltd. (1-1-12 Hama-cho, Nihonbashi, Chuo-ku, Tokyo, 101-0032, Japan)

 

(Received July 10, 2018; Accepted August 16, 2018)

 

Abstract

In this study, we investigated the amounts of total polyphenols and in vitro antioxidant activities of some aqueous extracts prepared from three kinds of green teas, one kind of oolong tea, and two kinds of black teas and their corresponding Kosenchas, which are produced by treatment with high pressure and high temperature. Only the yields of Kosencha from green teas were higher than those of their original teas. The amounts of total polyphenols tended to be decreased in all kinds of Kosencha as compared to their original teas. In addition, the scavenging activities of Kosencha against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals also tended to be lower than those of their original teas. In green teas, however, the amounts of total polyphenols and antioxidant activities on DPPH radicals were thought to be higher than their original teas when the infusions were prepared by using the same amounts of tea leaves. In another case, the scavenging activities of Kosencha against superoxide anion radicals tended to be increased as compared to those of their original teas. These results suggest that the antioxidant activities of Kosencha from green teas were not decreased as compared to their original teas and that the polyphenol components, such as catechins and their polymers, would contribute to the antioxidant activities.

Key words: Camellia sinensis, Tea, Kosencha, Polyphenol, Antioxidant