Comparison of total polyphenols in some imported black tea, Iranian black teas and fresh green leaf of the tea plant

Antioxidants, including polyphenols which are involved in food compounds, play a vital role in human‟s health. Some studies have shown that antioxidants reduce the risk of chronic diseases, such as cancer and heart disease. Tea (Camellia sinensis) is the second most popular beverage in the world, which has been considered as a valuable sourceof antioxidants because of its polyphenols contents. This study was conducted to measure total polyphenols in the different black teas such as imported black tea, Iranian black tea, and green tea. The results showed that the total polyphenol content varies from 11.86 to 20.99 (gr/100 gr d.w.). Accordingly, the polyphenol content of imported black teas in significance level probability of 5% was higher than Iranian black teas. Moreover, the results of the comparison between Iranian black and green teas showedthat the total polyphenol content of them are completely different in significance level probability of 5%. Thus, it seems that geographical locations, agronomic practices, processing steps and the quality of the fresh leave of the tea plants have a positive impact on total polyphenol content in manufactured black tea.

کلیدواژه ها:

Total polyphenols ، Iranian black tea ، Imported black tea ، Green tea ، Camellia sinensis