FOOD SCIENCE ›› 2013, Vol. 34 ›› Issue (6): 77-82.doi: 10.7506/spkx1002-6630-201306017

Previous Articles     Next Articles

Optimizing the extraction of tea polyphenols and theanine from summer green tea by using response surface methodology

ZHANG Xin1,ZHU Shi-gui2,XU Fei1,SUN Yi1,HU Bing1,ZENG Xiao-xiong1,*   

  1. 1. College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China;2. The Academy of Science, Nanjing Agricultural University, Nanjing 210095, China
  • Received:2011-12-06 Revised:2013-01-31 Online:2013-03-25 Published:2013-03-01
  • Contact: Xiaoxiong Zeng E-mail:zengxx2002@yahoo.com.cn

Abstract: The response surface methodology was used to optimize the extraction of tea polyphenols and theanine from summer green tea by hot water. Three parameters including extraction temperature, extraction time and ratio (v/w) of water to raw material were optimized based on tea polyphenols content, theanine content and antioxidant activity of the extracts. The optimal extraction conditions were extraction temperature 96.12 ℃, extraction time 40.32 min and ratio of water to raw material 15.91 mL/g for tea polyphenols (133.68 mg gallic acid/g), 98.55 ℃, 40.97 min and 12.61 mL/g for theanine (4.11 mg/g), and the extraction conditions that provided optimum IC50 value for DPPH free radical scavenging activity (722.17 ?g/mL) were 96.34 ℃, 40.27 min and 16.09 mL/g. Under the extraction conditions (96 ℃, 40 min and 16 mL/g), the predicted yields for tea polyphenols and theanine were 99.99 and 96.68% of their corresponding predicted values under their optimal extraction conditions, respectively. The results suggested that the regression models were accurate and adequate for the extraction of tea polyphenols and theanine from summer green tea.

Key words: response surface methodology, summer green tea, tea polyphenol, theanine, antioxidant activity

CLC Number: