Concentration of fluoride and selected other elements in teas

Area of Science:

• Food Science
• Analytical Chemistry
• Nutritional Science

Background:

• Tea is a widely consumed beverage globally.
• Understanding the mineral content of tea, particularly fluoride, is important for public health.
• Variations in tea processing and origin can influence mineral release.

Purpose of the Study:

• To quantify and compare fluoride and other elemental concentrations in various tea types.
• To investigate the infusion kinetics of fluoride release from different teas.
• To assess the impact of milk on fluoride levels and estimate daily fluoride intake.

Main Methods:

• Infusions were prepared from Chinese, Ceylon/Indian, and herb teas using deionized water at 85°C.
• Elemental analysis was performed for Fluoride (F), Phosphorus (P), Calcium (Ca), Aluminum (Al), Magnesium (Mg), Manganese (Mn), and Zinc (Zn).
• Infusion times varied to study release kinetics; milk addition was tested.

Main Results:

• Chinese teas showed sustained fluoride release over 60 minutes, while Ceylon/Indian teas released fluoride mainly within 5 minutes.
• Mean fluoride concentrations after 15 minutes were 1.73 ppm for Chinese teas and 1.24 ppm for Ceylon/Indian teas.
• Herb teas had negligible fluoride; Phosphorus and Magnesium were abundant. A strong correlation (r=0.81) existed between released fluoride and aluminum. Milk did not significantly alter fluoride levels.

Conclusions:

• Chinese teas are a greater source of fluoride compared to Ceylon/Indian teas due to differential release rates.
• Fluoride intake from tea is influenced by tea type and brewing time.
• Estimated daily fluoride intake from tea, especially when brewed with fluoridated water, warrants consideration in dietary assessments.