Investigation of the content of multiple elements and tea-polyphenol in the tea planted in Guangdong

ObjectiveTo investigate the contents of eight elements and tea-polyphenol in the common tea grown in Guangdong.MethodsThree kinds of representative tea samples (green tea, oolong tea and black tea) were collected from seven tea producing areas in Guangdong Province from 2017 to 2018. The contents of eight mineral elements and tea polyphenols were measured and compared in the tea from different producing areas with national standard method.ResultsThe tea planted in Guangdong are rich in macroelements (K, Ca and Mg) and microelements(Fe, B and Mn). The contents of potassium and calciumiron in oolong tea were 19.0 and 3.29 g/kg; the contents of iron in green tea was 0.174 mg/kg; the contents of Mg, P, Mn and Se in the three kinds of tea were similar. The contents of tea polyphenols and catechins in green tea were higher than those in oolong and black tea, and the contents of epigallocatechin gallate in different teas were generally higher than those of the other four catechins.The content of K in the tea from Ch