PURSE 2006

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https://ir.lib.pdn.ac.lk/handle/20.500.14444/53

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Browsing PURSE 2006 by Author "Illeperuma, D. C. K."

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    Antioxidant capacity of different types of Sri Lankan tea
    (University of Peradeniya, Sri Lanka, 2006-11-30) Thilakarathna, R. M. M. S.; Nissanka, S. P.; Illeperuma, D. C. K.
    Although Sri Lanka has been exporting tea mainly as black tea, antioxidant capacity was not adequately exploited for value addition to promote marketing. For exploitation, knowledge on antioxidant capacity of our made-tea, which might vary mainly with clonal characteristics, climatic conditions and manufacturing methods, is essential. This study was initiated to investigate the variation of antioxidant capacity of made-tea based on different cultivars, tea type (green or black tea), grades and the influence of seasonality (quality season vs their season). Black tea samples (100 g from each grade) were collected from Pedro and Samia Estates separately to fulfill research objectives. Commercial scale orthodox manufacturing process was practiced in the estates and manufacturing conditions were the same for all the collected black tea samples. Green tea grades were collected from Oliphant estate. Ten different black tea grades from three different cultivars (PK-2, TRI 2025 and Seedling-tea) and six green tea grades from cultivar PK-2 were obtained. To check the seasonal effects on black tea, ten different grades were collected from Nuwara Eliya (Dimbula season: December to March and off season) and Uva region (Uva season: July to September and off season). Herbal teas were purchased from Canada. The total antioxidant activity (TAA) of brewed tea samples was analyzed using DPPH method and it specifies a spectrophotometric method used in determining the antioxidant activity of tea with respect to Trolox (water soluble Vitamin E analog), by a DPPH (which is a free radical) assay. TAA of tea samples were extrapolated using a standard series and trolox® was used as the standard antioxidant. The cultivar TRI 2025 has 1.8 fold and 1.3 fold greater TAA compared to PK-2 and Seedling-tea respectively (p