کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4564731 | 1330947 | 2008 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effect of different brewing methods on antioxidant properties of steaming green tea Effect of different brewing methods on antioxidant properties of steaming green tea](/preview/png/4564731.png)
The extracts were prepared from cold or hot brewed steaming green tea at different concentrations (2, 6, and 10%), its antioxidant properties studied and potential antioxidant components determined. The yields of hot water extracts (17.49–28.27%) were significantly higher than those of cold water extracts (11.72–14.70%). EC50 values in antioxidant activity determined by the conjugated diene method and reducing power were 2.19–3.10 and 0.22–0.28 mg/ml, respectively. EC50 values in scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals were 29.45–43.80 and 2.88–3.22 mg/ml, respectively. EC50 values in chelating ability on ferrous ions were 6.45–13.51 mg/ml. Contents of total phenols were 221.71–330.22 mg/g whereas those of total catechins in cold and hot water extracts were 135.05–193.14 and 161.57–195.05 mg/g, respectively. Based on the results obtained, hot water extracts were more effective in antioxidant activity and reducing power. However, cold water extracts were more effective in scavenging ability on DPPH and hydroxyl radicals, and chelating ability on ferrous ions. Summarily, the cold brewing method would be a new alternative way to make a tea.
Journal: LWT - Food Science and Technology - Volume 41, Issue 9, November 2008, Pages 1616–1623