Keywords : Total Ionic Strength Adjustment Buffer
Engineering and Technology Journal,
2013, Volume 31, Issue 6, Pages 167-173
The fluoride contents in the infusions of (10) commercially available in the local market in Iraq of tea brands in leaf and bag forms was determined by a fluoride ion-selective electrode method. The effect of brewing time on fluoride release from tea was assessed. Results showed that fluoride release increased with increasing brewing time (3, 5 ,10 min). Fluoride level after 5 min brewing for
green tea bags, black tea leaves and black tea bags was in the range of (80mg/kg),(122~309mg/kg)and(308~348 mg/kg) respectively .The WHO guideline for daily fluoride intake is( 2.00 mg) for children and ( 4.00 mg) for adults. Assuming that one consumes 4 cups of tea everyday (400 mL) and each cup uses (2.5 g ) of tea leaves, the daily fluoride intake from black tea leaves may be in the range ( 1.22 ~ 3.09 mg ). Similarly, intake from the green tea bags about (0.80 mg). Similarly, intake from the black tea bags may range from (3.01 ~ 3.45 mg ) . Thus according to the WHO recommendation for daily fluoride intake the black and green tea bags and black tea leaves are safe for all age groups .