Tea leaves contain unsaturated fatty acids which are precursors of aroma compounds. Despite uniform plucking practices in Kenya, plain black tea quality varies with locations. Variations in tea aroma and/or precursors with production area have not been established in a single cultivar under same agronomic input at different locations. Trials were conducted in five locations using clone BBK 35, harvested at varying intervals. The fatty acids varied (P ≤ 0.05) with locations and increased (P ≤ 0.05) with long plucking intervals, demonstrating leaf of same standard plucked at varying intervals contains different levels of fatty acids even in one location. The different increase rates in various locations might be in part the reason of the differences in aroma of black tea from different locations even when agronomic inputs are similar. Results demonstrate that harvesting at shorter intervals and developing region-specific plucking policies may improve tea quality.Keywords: tea, Camellia sinensis, fatty acids, plucking interval, location of production *To whom correspondence should be addressed. E-mail: owuorpo@africaonline.co.ke
IntroductionTea (Camellia sinensis (L.) O. Kuntze) yields and black tea quality are influenced by agronomic practices, especially plucking (Owuor, 1996). Plucking is an expensive undertaking (Ellis and Grice, 1981) and constitute up to 80% of the total field cost of tea production (Sharma, 1987). During this process young tender shoots are harvested for processing into various tea beverages. The recommended plucking standard in tea is two leaves and a bud that gives desirable good quality teas (Othieno, 1988), although there are producers harvesting mature leaf. In practice, it is very difficult to exclusively achieve the recommended standard in commercial tea harvesting as various portions of different standards leaf are usually plucked and the amount of coarse fraction and fine fraction in the plucked crop determines the overall leaf quality.Shoots of similar two leaves and a bud can be obtained through optimizing harvesting intervals when most leaves are in the stage of two leaves and a bud. Plucking frequency is therefore an important factor which controls the proportions of different leaf standard in the harvested crop (Odhiambo, 1989) and influences yield (Owuor et al., 2009) and tea quality (Baruah et al., 1986, Owuor et al., 2009. Flavoury black teas are valued for their unique smell attributed to the levels and distribution of the volatile flavour compounds (VFC) (Robison and Owuor, 1992) while plain teas are valued for their taste, briskness and colour characteristics, which are influenced by non-volatile (theaflavin and thearubigin) components. The VFC in tea can further be classified into primary and secondary products (Sanderson and Graham, 1973). The primary aroma compounds are biosynthesized by the plant and are present in the fresh tea leaf, while the secondary products are derived from carotenes, amino acids, unsaturated fatty acids and other lipids (Robinson and Owuor, 19...