Adulteration detection of tea samples based on plant rbcL gene sequencing

Abstract:

Tea is one of the most popular drinks in the world, but counterfeit or adulterated tea can be found now and then on the tea market. The traditional methods dependent on sensory, physical and chemical tests cannot identify the composition of adulterated plant species accurately. We developed therefore a method for identification of adulterated plants in tea based on qualitative detection of plant rbcL (Ribulose 1,5-bisphosphate carboxylase-oxygenase large subunit) fragments, which involved amplification, sequencing and sequence analyses of rbcL fragments. Seven tea samples were analyzed with the established method. The results showed that Yueyanghuangcha (yellow tea) and Xinyangmaojian (green tea) were pure with only detection of the tea plant Camellia sinensis; Zhengshan Souzhong (black tea), Tieguanyin (oolong tea), Tailaoyinzhen (white tea), Liupao and Pu-erh (dark tea) were, to a certain extent, adulterated with non-Camellia sinensis plants. The method introduced in this study only requires a small amount of tea samples, easy to operate and reliable. It can be used to determine if any tea samples are adulterated.