a study on the effect of harvesting season and brewing condition on total polyphenole content in the iranian green tea

green tea is prepared from the leaves of camellia sinensis. catechins of green tea are well known as natural antioxidants and have effective beneficial on the body. one of the most important processes in the extraction of catechins and producing green tea beverage is brewing process. the object of this study is to investigating the effect of brewing temperatures (60٫70 and 80˚c) and duration (5٫10 and 15 min) also the season effect of plucking on green tea that was produced in the tea research foundation of lahijan. results of total phenolic content on brewed green tea, is showed that plucking in summer and spring seasons samples have much total phenolic content are rather than plucking in autumn season samples also percent extraction of brewing green tea at 15 minuets has most highest total phenolic content than other seasons and brewing times .brewing temperature are not significant effected on the total phenolic content.