Investigation of Biochemical Changes of Green Tea Leaves Treated with Boric Acid in Different Harvest Periods

Tea obtained from C. sinensis leaves has different pharmacological effects such as antioxidative, pro-oxidative and anticarcinogenic. The lack of boron elements required for the growth and development of plants causes the production of reactive oxygen species. It has been reported that high boron concentration also increases the antioxidant enzyme activity and protects the membrane functions from the damage of reactive oxygen species. The aim of this study was to investigate the biochemical changes of green tea leaves treated with boric acid in different harvest periods. ？aykur trial garden was divided into 20 parcels in Rize-？ayeli district. Groups were formed by applying boric acid to C. sinensis at concentrations of 0 (group A), 100 (group B), 300 (group C) and 500 (group D) mg/m2. During three harvests, green tea leaves were collected and fixed in liquid nitrogen. The catalase (CAT), superoxide dismutase (SOD) enzyme activities and glutathione (GSH), malondialdehyde (MDA) levels of green tea extracts were determined. SOD enzyme activity and GSH level were high especially in the 3rd harvest period, and also B and D groups were significantly higher than A group (p <0.05). There was a decrease in the B, C and D groups at the MDA level in the 1st harvest period compared to the A group (p <0.01). According to our findings, the lack of boric acid in the soil where green tea leaves grow can reduce the protective properties of tea. Better quality products with antioxidant properties can be provided with tea leaves obtained from boric acid applied areas