Studies on some heavy metal residues in fresh Oreochromis niloticus [electronic resource]: trails to reduce them by marination and heat treatment.

Includes references.

A total of forty fresh Oreochromis nilolicus were collected from markets of Kalubia governorate to estimate the level of, lead (Pb) , cadmium (Cd) and mercnry (Hg) residues. Heavy metal residues were estimated in raw samples then after marination with garlic, lemon and other additives after one hour and two hours then after roasting and frying of marinated samples by using Atomic Absorption Spectrophotometer (AAS) .The obtained res nits revealed that lead levels were within permissible limits in all raw samples while cadmium and mercury levels were higher than the permissible limits in 70% of raw flesh fish samples. Marination of fish samples with garlic, lemon and other additives for two hours decreased lead and mercury levels. Also roasting and frying of marinated samples decrease Hg and Pb levels .Meanwhile they had alittle effect on Cd level .The present results were evaluated according to the permissible limits of FAO / WHO (1992) and Egyptian Organization for Standarization and Quality Control (E.O.S.Q.c.) (1993) and (2004). Finally it is concluded that careful periodical analysis of fish should be performed to evaluate their load of heavy metals. Good cooking and marinating of fish flesh for two hour~ and more should be done to avoid the hazards of heavy metal on human health. Moreover, the.public health significance and suggested precautions for minimizing the level of such heavy metal residues in fish were discussed.

Summary in Arabic.

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