Climatic variation of antioxidative properties, phenolic and mineralnutraceuticals in tea (Camellia sinensis (L.) Kuntze) grown in North Bengal, district Darjeeling

Climatic variation of anti-oxidative properties, Phenolics and mineral nutraceuticals in fresh tea shoots, consisting of one apical bud and two adjoining leaves sampled from TV1, TV20, TV26, TV29, TV30 (Tocklai Vegetative) clone and Tingamara, Dangri Manipuri and Sundaram B/5/63(Seed jat) grown in Terai region in Darjeeling district, North Bengal was investigated during three harvest season (March, June and December) in 2007, 2008 and 2009. The total Phenolics of all clones were lower in cool months of December in three years (average 36.02-93.29 mg GAE/g dry weight basis). Thereafter, the levels of total Phenolics increased throughout the warmer months from March to September. Antioxidant activity determined by Antioxidant activity determined by DPPH based free-radicals scavenging assay showed similar trends which increased from 1st harvest (March) to 3rd harvest (December). All clones showed nearly 100% antioxidant activity at 2nd and 3rd harvest season which higher than standard synthetic antioxidant BHA (Butylated hydroxyl anisole). However, seasonal variation of minerals (N, P, K, Ca, Mg, Na, Fe, Cu, Mn, and Zn) showed different results according to clones used. These results seem to suggest that the harvest time is crucial to determining the antioxidant potential of fresh tea shoots.