Distribution of trace elements in tissues of two shrimp species from persian gulf and effects of storage temperature on elements transportation

This study is focussed on evaluation of temperature effect during frozen storage on movement of trace elements in different tissues (exoskeleton, carapace and abdominal muscle) of two commercially important shrimp species (Penaeus merguiensis and Metapenaues affinis). Moreover relationships between total length and sex of specimens with concentration of trace elements in selected tissues were assessed. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn in samples were determined by ICP-AES. Only in the case of Ni and Zn sex related differences could be observed. With the exception of Cu, the trace metals distributed significantly different between the tissues. The only significant differences between species were found in bioaccumulation of Mn. Size dependent relationship was observed only for Ni. Associations between Mn and Fe were positively and highly significant in all the cases. The levels of all the metals in muscle of the shrimps from the studied region were comparable to other world areas. Mean Cu and Zn levels in edible parts of M. affinis stored at -10 degreesC exceeded some existing guidelines, while the concentrations at -30 degreesC were somewhat lower than them.