Nutritional and Functional Characteristics of Seven Grades of Black Tea Produced in Turkey
详细信息 查看全文
- 作者：Arda Serpen ; Ebru Pelvan ; Cesarettin Alasalvar ; Bur莽e Ata莽 Mogol ; Havvana Tuba Yavuz ; Vural G枚kmen ; Nihat 脰zcan ; Beraat 脰z莽elik
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2012
- 出版时间：August 8, 2012
- 年：2012
- 卷：60
- 期：31
- 页码：7682-7689
- 全文大小：253K
- 年卷期：v.60,no.31(August 8, 2012)
- ISSN：1520-5118
文摘
Seven grades of black tea [high-quality black tea (grades 1鈥?) and low-quality black tea (grades 4鈥?)], processed by 脟AYKUR Tea Processing Plant (Rize, Turkey), were examined for their proximate composition, dietary fiber, minerals, and water-soluble vitamins as well as total phenolic content, various antioxidant assays, phenolics (flavanols, alkoloids, condensed phenolics, and phenolic acids), chlorophylls, and carotenoids. Some variations, albeit to different extents, were observed (p < 0.05) among these parameters in seven grades of black tea. With respect to proximate composition, dietary fiber was the predominant compound (ranging from 49.68 to 54.31 g/100 g), followed by protein, carbohydrate, and, to a lesser extent, ash, moisture, and fat. Thirteen minerals, four water-soluble vitamins, six flavanols, two alkoloids, three condensed phenolics, one phenolic acid, two chlorophylls, and two carotenoids were identified in the seven grades of black tea. Total phenol content ranged from 7.52 to 8.29 g of gallic acid equivalents (GAE)/100 g, being lowest in grade 6 and highest in grade 1. With regard to antioxidant activities, a large variation in oxygen radical absorbance capacity (ORAC) values was observed among all grades of black tea (ranging from 777 渭mol of trolox equivalents (TE)/g in grade 7 to 1210 渭mol of TE/g in grade 3). The present work suggests that high- and low-quality black teas should not be distinguished on the basis of their nutritional and functional characteristics. The combination of nutritional compounds together with functional characteristics renders combination effects that provide the characteristic quality of each grade of black tea.