Trace elements in Camellia sinensis marketed in southeastern Brazil: Extraction from tea leaves to beverages and dietary exposure
The presence of Al, As, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in 30 samples of tea (Camellia sinensis) purchased from markets in southeastern Brazil were evaluated by ICP MS. This study was performed for both tea leaves and their infusions. The results provide data that permits an evaluation of the exposure or dietary intake of these trace elements. For some samples, the levels in the tea leaves were above the standards established by the Brazilian and MERCOSUL regulatory bodies. For example, As was detected in 33% of the red oolong tea samples and Pb was detected in 67% and 100% of the white and red oolong samples, respectively. Although some of these tea leave samples possessed high toxic elements levels, the concentrations of the trace elements in the infusions were measured to be at safe levels. An evaluation of dietary intake demonstrated the remarkable importance of tea in achieving the daily intake of manganese. Indeed, a single cup of green tea may provide 16% of the daily value established by FDA. Principal component analysis classified the tea into three distinct groups on the basis of the inorganic constituents in the tea leaves.