Abstract

The present study aimed to investigate the fluoride concentration in tea leaves of different types of commonly used Iranian tea and the influence of brewing time and water hardness on fluoride release during their infusion. The concentrations of fluoride, phosphate, sulfate, nitrate, and chloride were measured, after 3 to 120 min brewing time, in 100 tea samples, including white, green, oolong, and black teas. The daily fluoride intake was also assessed. The fluoride concentration was measured with the ion chromatography method. The results showed that the minimum and maximum concentrations of fluoride in the tea liquor, after 15 min infusion, were 1.46 and 2.9 mg/L in teas made with oolong tea leaf and green tea leaf, respectively. Fluoride release from the tea leaves into the infusion increased significantly with increased brewing time (p<0.05). Fluoride release, after a 15-min brewing time, ranged from 43.7 for green tea bag to 73.5 for black tea leaf. Fluoride extraction was less in hard water. © 2016 The International Society for Fluoride Research Inc.