Mineral Contents and Leaching Characteristics in Green Tea from Hanzhong, Shaanxi

The contents of six mineral elements including Mn, Zn, Fe, Cu, Ni and Cr in the digested solutions and infusions of seven kinds of green tea from the main tea-growing region of Hanzhong, Shaanxi province were determined by atomic absorption spectroscopy(AAS). The quality evaluation of green tea from Hanzhong was carried out with respect to mineral contents and leaching rates. The recoveries for six metal elements were between 92.70% and 102.55% with relative standard deviations less than 10%. The results showed that AAS enabled simple, rapid and accurate determination of mineral contents in green tea and its infusion. Based on the mineral contents and leaching rates, the quality of organic zinc and seleniumenriched tea, Pengxiang tea powder, Hangzhong Xianhao and Hanzhong green tea was better than that of other green tea samples tested.