Determination of mineral and toxic heavy elements in different brands of black tea of Pakistan

Camellia sinensis (Tea) has attracted attention of consumers and food manufacturers for its health benefits and physiological effects. Evidences are found that heavy metals are present in tea. Both metallic and non metallic elements are essential for human growth and development within certain permissible limits; harm to humans is expected due to change in this allowable limit. Twelve black tea samples (open and branded) were collected from market and subjected to analysis, using flame atomic absorption spectroscopy. The results showed that black tea available in market is made from leaves collected from different regions (different soil source), and have different capacity for accumulation of heavy metals. Key words: Black tea, heavy metals, flame atomic absorption spectrometry (FAAS), toxicity. INTRODUCTION For so long herbs are utilized for the treatment of different kind of disease. Tea which is used as refreshing drinks has been widely used in the past and also in the present, all over the world. It can be easily prepared from fresh or dried herbs by putting hot water in it. Depending on the chemical constituents present in herbal tea, it is utilized for nutritional as well as therapeutic purposes. It is evident from botanical study that tea is the most largely consumed beverage in the world. Different investigation showed that tea particularly green is useful for prevention of cancer, use as a stimulant, astringent, diuretic, regulate body temperature and blood sugar, promoting digestion and increase mental activity. Some toxic heavy metals are described in literature from herbs (Samali et al., 2012). Saponin isolated from tea has been