CHED 233 |
| Tea is the oldest caffeinated beverage in recorded history with a legendary origin in China. Tea is a principal beverage world-wide, drunk by many different cultures. It is also the second largest source of phenolic antioxidants in the US diet. Consumers now have a wide choice of both green and black tea. Methods of preparation and consumption are varied and include instant powder, bag, leaf, bottle, and cans, as well as decaffeinated tea. The USDA Flavonoid Database, updated in 2007, measured only several catechins in commercial teas and, thus, only a few of the compounds present in tea. In addition, some of the phenolic compounds are conjugated and not analyzed by the USDA HPLC method. Thus the amount of polyphenols found in tea has been underestimated. We have measured the total phenols in commercial teas following a basic hydrolysis, coupled with solid phase extraction to remove interferences. Ox-redox colorimetry was used to analyze the free and total amount of polyphenols in teas. Results will be discussed and comparisons made of the different teas. |
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Undergraduate Research Poster Session: Analytical Chemistry
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |