Determination of Fluoride in the Ethiopian and Imported Black Tea (Camellia sinensis) Infusions Prepared in Tap and Fluoride Rich Water
No Thumbnail Available
Date
2011-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
Abstract
Tea leaves are very rich in fluoride, since the tea plant take up fluoride from the soil and
accumulate in its leaves. Depending upon the fluoride content of the water, dried tea leaves are
also able to absorb fluoride from water with high fluoride level. In this study, the possible effect
of original fluoride concentration in natural water on the fluoride release from tea has been
investigated and also conductivity, salinity, TDS and pH of naturally fluoride rich water and the
tea infusions prepared in deionized water, tap water and fluoride rich water have been
determined. Moreover, the possible capacity of tea leaves (commercially available tea) to absorb
fluoride from naturally high-fluoride water which were collected from Ethiopia Rift Valley
where the fluoride level of water is high has been investigated.
Infused fluoride content, conductivity, salinity, TDS and pH of black (either powder or bag
form) and green (bag form) teas and different water (sampled from Ethiopia Rift Valley) were
assayed. Fluoride ion selective electrode, conductivity meter and pH meter were used to
determine the fluoride content, conductivity, salinity, TDS and pH of the six naturally different
types of water, nine brands of tea prepared in deionized water, tap water and naturally fluoride
rich water whose origin from Ethiopia, Sri Lanka and China. The fluoride content, conductivity,
salinity, TDS and pH of six naturally different water ranged from 0.254-30.2 mg/L, 2.27-1706
μs, 0-0.9 %o, 48.7-838 mg/L and 7.73-8.59, respectively, infused fluoride, conductivity, salinity,
TDS and pH in nine brands of tea ranged from 50.8-2057 mg/kg, 414-2377 μs, 0.2-1.2 %o, 196-
1180 mg/L and 4.83-8.52, respectively, which were prepared in naturally different types of water
in different brewing time (3, 5 and 10 min) infusion. Even though, the fluoride level of tea
prepared in naturally fluoride rich water is high, one can reduce the daily intake of fluoride level
by taking tea rather than taking the naturally fluoride rich water itself.
Keywords: naturally fluoride rich water, fluoride, tea infusion, brewing time, ISE
Description
Keywords
Naturally fluoride rich water; fluoride; tea infusion; brewing time; ISE