Assessment Of Fluoride In The Ethiopian And Imported Black And Green Tea (camellia Sinensis) Infusions Measurement And Safety Evaluation

The fluoride contents in the infusions of 21 commercially available Ethiopianrnand imported black and green tea brands; in leaf and bag forms wasrndetermined by fluoride ion-selective electrode. Of the samples analyzed 12 ofrnthem were products of Ethiopia. It is found that fluoride level increases withrnincreasing brewing time (3, 5 and 10 min). The present study revealed widerndifferences in fluoride levels. Fluoride level of black tea leafs after 5 minrnbrewing, which is the common time used to prepare tea infusions, was in thernrange of 117 – 682 mg/kg, for green tea bags it was between 111 – 190 mg/kgrnand that of black tea bags fluoride concentration was in the range of 141– 246rnmg/kg. While the Ethiopian black tea leafs fluoride level ranges from 248 torn682 mg/kg with mean concentration of 458 mg/kg among ten brands. Of thernimported products, teas of the same brand, the fluoride content was greatest inrnblack tea bags, presumably because black tea bags are made from low costrnolder tea leaves. While the fluoride level in green tea was found lesser, as greenrnteas are made from young shouts of the plant which contain less amount ofrnfluoride. On the basis of the results obtained, the daily intake of fluoridernprovided from tea was estimated for an adult person and for children inrncomparison with the WHO guide line for daily fluoride in take thresholds Which is 2 mg for children and 4 mg for adults. Assuming that one consumesrn4 cups of tea everyday (400 mL) and each cup uses 2.5 g of tea leaf or one tearnbag, daily fluoride intake through taking the black tea leafs may be 1.11 – 6.82rnmg, 1.00 - 1.38 mg through green tea bags and from the black tea bags it mayrnrange from 0.86 – 1.81 mg. from the Ethiopian black teas alone, the dailyrnfluoride intake may range from 2.48 – 6.82 mg. Thus according to the WHO,rn2002 recommendation for daily fluoride intake threshold and no or very lessrnamount fluoride from other sources; all the black and green tea bags; andrnimported black tea leafs were safe for all age groups. From the 10 Ethiopianrnblack tea leaf brands none of them were safe for children but 30% of them werernsafe for adults.rnThus, the control of tea quality is important to protect human against too highrnuptake of this element from black tea, which is the most popular beverage.rnExcessive intake of fluoride with black tea, especially in the regions with itsrnhigh level in the drinking water, increases the risk of dental fluorosis inrnchildren during the years of tooth development. The long-term exposure tornlarge amounts of fluoride can lead to potentially skeletal fluorosis.rnKeywords: Black Tea Infusion, Green Tea Infusion, Fluoride, Brewing Time,rnSafety Evaluation, ISE

Get Full Work

Report copyright infringement or plagiarism