Contamination of Copper, Iron, Zinc, Manganese and Aluminium During the Black Tea Process

Authors: A. Cihat KÜTÜK, Burhan KACAR

Abstract: The contamination rates of copper, iron, zinc, manganese and aluminium during the black tea process were evaluated. Total 1411tea samples were collected from 18 tea factories of General Directorate of Tea Enterprise (‚aykur) and 4 tea factories of Private Sector. Copper, iron, zinc, manganese, aluminium contents of tea samples were determined by Atomic Absorption Spectrophotometer. The highest contamination of copper and zinc to the tea occurred in the Orthodox method. On the other hand, iron and aluminium contamination were found to be maximum in the C.T.C. method. Copper and aluminium contamination were statistically highly significant in the curling process of the Orthodox method and C.T.C. process of the C.T.C. method. Iron and zinc contamination occurred to be highest in the classification process of the black tea. Coating materials of the curling machines have influenced on the contamination rate of tea significantly. There was no copper contamination in the factories having curling machines coated with chrome-nickel. On the other hand, the high copper contamination was found in the black tea produced in the factories of General Directorate of Tea Enterprise having curling machines coated with bronze. Similarly, iron and aluminium contamination were determined to be high in the factories having curling machines coated with bronze. The shooting periods affected significantly on the iron, zinc, manganese and aluminium contents of the tea except copper. On the other hand, manganese and aluminium contents of the tea increased while iron and zinc contents decreased depending on to the shooting periods.

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