Seasonal climate effects on flavanols and purine alkaloids of tea (Camellia sinensis L.)

The seasonal climate changes and their effects on flavanol and purine alkaloid contents of two leaves and a bud of tea were evaluated among 3 cultivars grown in Hangzhou, China. The results showed (−)-epigallocatechin (EGC), (−)-epicatechin (EC), (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG) increased, but (+)-catechin (C) decreased with increasing daily average temperature (DAT). Long period of precipitation (PRE) led to the declines of EGC, EC, ECG, EGCG and their total content (TC) but increased C content. Furthermore, relative humidity (RH) significantly affected EGC, TC and caffeine. Therefore, DAT, PRE and RH should not be ignored in tea production. The order of climate dependence according to the regression models was C > EGCG > TC > EGC > EC > caffeine > ECG > theobromine, indicating seasonal climate had greater effects on flavanols than purine alkaloids.