PHARMACEUTICAL BIOLOGY, cilt.46, ss.683-687, 2008 (SCI-Expanded)
Seasonal variations of total phenolic, antioxidant activity, PNE ( Plant Nutrient Elements), and fatty acids in fresh tea leaves grown in Turkey were studied. Fresh tea leaves sampled from Derepazari 7 clone [ Camellia sinensis L. var. sinensis ( Theaceae)] were analyzed and compared during the three commercial harvest seasons ( May 15, July 15, and September 15) in both 2005 and 2006. The levels of total phenolics and antioxidant activity was higher at 2nd harvest time ( 62.88 mu g/mg and 89.27%). The seasonal variations of the individual fatty acids were significant ( P < 0.05) between the three harvest seasons. The amount of N and P in tea leaves was the highest at 1st harvest; however K, Ca, Mg, S, and Mn were highest at 2nd harvest time. This study revealed that total phenolics could be used as quality descriptors for monitoring the seasonal variations in Turkey-grown tea leaves.