Optimal Reaction Conditions and Radical Scavenging Activities for the Bioconversion of Green Tea Using Tannase
Tannase를 이용한 녹차의 생물학적 전환의 최적 조건 마련 및 라디칼 소거능

Yang-Hee Hong, You-Kyung Yeon, Eun-Young Jung, Kwang-Soon Shin, Kwang-Won Yu, Tae-Young Kim, Hyung-Joo Suh
2011 Journal of the Korean Society of Food Science and Nutrition  
In this study, we optimized the reaction conditions for the bioconversion of green tea using tannase, and to evaluate its radical scavenging activities. Tea catechins such as (-)-epigallocatechin gallate (EGCG) or (-)-epicatechin gallate (ECG) were hydrolyzed by tannase to produce (-)-epigallocatechin (EGC) or (-)-epicatechin (EC), respectively, and a common product, gallic acid. The bioconversion of tea catechins by tannase was increased as enzyme concentration, substrate concentration and
more » ... bation time for enzyme dose. The results indicated the optimum reaction conditions for tannase were tannase 30 U/mL (enzyme concentration) on 1% green tea (substrate concentration) for 1 hr (incubation time for enzyme). Tannase enhanced the radical-scavenging properties of green tea; the 2,2-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging abilities were significantly (p<0.001) greater for the tannase-treated green tea extract compared to the untreated green tea extract. It is reported that ECG has the greatest antioxidant activity among the catechins in green tea, and the release of gallic acid is considered to be beneficial because of its significant antioxidant potency. The results of this study suggest that the tannase-treated green tea increases antioxidant activities under optimum reaction conditions.
doi:10.3746/jkfn.2011.40.11.1501 fatcat:6ezwosjujffp5lkurgnb2k26ly