The effect of ascorbic acid and lemon juice on the extraction of metals from green tea, health risk assessment

Abstract

The total heavy metal concentration (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in green tea leaves and metals leached into tea infusions of pure water with the addition of ascorbic acid and lemon juice at various temperatures (70, 80, and 100 °C) and steeping times (3, 5, and 7 min), were determined. Metal concentrations were analyzed by atomic absorption spectrometry and the flame technique (FAAS). Mean total concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn were < LOD, <LOD, 0.198, 4.527, 67.51, 333.7, 2.588, <LOD, 10.23 μg/g, respectively. The highest percentage of extraction in different solutions was in the case of Mn (up to 100%). The risk for adults through consumption of tea was mainly contributed by Mn, and non-carcinogenic hazard quotient (HQ) was slightly higher than 1 when infusions were heated to 100 °C. High percentages of Ni were extracted in pure water compared to water with addition, regardless of tea steeping time, followed by Cu in pure water and water with lemon juice. Fe was poorly extracted in all applied solutions; the highest percentage of extraction (17.21%) was determined in lemon juice solutions of at 100 °C during a steeping time of 7 min.