TY - JOUR ID - 5914 TI - Effect of different brewing times on antioxidant activity and polyphenol content of loosely packed and bagged black teas (Camellia sinensisL.) JO - Avicenna Journal of Phytomedicine JA - AJP LA - en SN - 2228-7930 AU - Nikniaz, Zeinab AU - Mahdavi, Reza AU - Ghaemmaghami, Seyed Jamal AU - Lotfi Yaghin, Neda AU - Nikniaz, Leila AD - Liver and Gastrointestinal disease research center, Tabriz University of medical sciences, Tabriz-Iran AD - Nutrition research center, Tabriz University of medical sciences AD - Nutrition Research Centre, Tabriz University of medical sciences, Tabriz-Iran AD - Student Research Committee, Tabriz University of medical sciences AD - Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, Tabriz-Iran Y1 - 2016 PY - 2016 VL - 6 IS - 3 SP - 313 EP - 321 KW - Antioxidant KW - polyphenol KW - Tea KW - Infusion time DO - 10.22038/ajp.2016.5914 N2 - Objective: Determination and comparison of the effect of infusion time on the antioxidant activity and total polyphenol contents of bagged and loosely packed black teas. Materials and Methods: For twenty loosely packed and eleven bagged tea samples, the antioxidant activity and total polyphenol content were analyzed using FRAP and Folin-Ciocalteau methods, respectively. The ANOVA with Tukey post-hoc test and independent t-test were used for statistical analysis. Results: The antioxidant activity and polyphenol content of various brands of tea samples were significantly different. There were significant differences in the antioxidant activity of loosely packed teas between 5, 15(p=0.03), 30(p=0.02) and 60(p=0.007) minutes of brewing times. Besides, there was a significant difference in antioxidant activity of bagged samples infused for 1 minute with four other infusion time points (p<0.001). In the case of polyphenol content, in loosely-packed tea samples, there were not significant differences between different brewing times (p=0.15). However, in bagged samples, the polyphenol contents of samples that were brewed for 1 minute were significantly lower than samples brewed for 3, 4, and 5 minutes (p<0.05). The antioxidant activity and polyphenol content of tea bags were significantly higher than those ofloosely-packed forms of the same brands at 5-min of brewing time (p<0.001). Conclusion: The infusion time and the form of tea (loosely packed or bagged) were shown to be important determinants of the antioxidant activity and polyphenol content of black tea infusions in addition to the variety, growing environment and manufacturing conditions. UR - https://ajp.mums.ac.ir/article_5914.html L1 - https://ajp.mums.ac.ir/article_5914_3d176e56b627d07159c6ae3201331d89.pdf ER -