| High concentration's fluorine is benefit and also harmful to people's health. Tea is fluorine-rich plant. Moreover, for produced by the aged raw material, the level of fluorine in Fuzhuan Tea is even higher than other cultivars. Some epidemiological investigations has shown that Fuzhuan Tea drinking is being related to florosis in minority area of China.Our research is conducted to promote a healthy way of tea drinking by analyzing the fluorine status of Fuzhuan Tea, as well as to decide the necessity of fluoride-reducing and the proper fluorine level via the study of general toxicity.Our studies can be summarized as follows:1. Factors influencing the digestion kinetics of fluorine in the Fuzhuan Tea was studied with an ion specific electrode methodology. The result showed that the dissolution rate of fluorine in the Fuzhuan Tea was correlated with the boiling (or infusing) time and expressed in a logarithm function curve. The smaller of the ratio between tea and water, the higher of the fluorine dissolution rate in Fuzhuan Tea. The dissolution rate of fluorine in the Fuzhuan Tea was correlated with the boiling(or infusing)time and expressed in an exponential function curve. Both with boiling or infusing, with the increasing of brewing time the dissolution rate of fluorine in the Fuzhuan Tea reduced significantly, most of the fluorine extracting in the first infusion. The smaller the size of tea, the easier fluorine to dissolute.2. The Chronic toxicology experiment of fluorine in the Fuzhuan tea was carried out by using the instant Fuzhuan tea prepared by water extraction and alcohol sedimentation technique as material in order to evaluate its safety for the rat. The results showed that during the 90 days fed by the instant Fuzhuan tea with 18mg/L,12 mg/L and 6 mg/L F- while the positive control group fed by NaF water with the same CF- as Fuzhuan tea group. Rats in the instant Fuzhuan tea group with 18mg/L F" and all of the positive control group were chronic fluorosis; rats in the instant Fuzhuan tea group with 12mg/L and 6mg/L F- grew well, with no dental fluorosis appeared; organ coefficient and histopathological characteristic of rats in these groups showed no significantly difference (P＜0.05), which suggested that fluorine in the Fuzhuan tea with these CF- was safe for experimental animal. |
