THE VALIDITY OF SOME DOMINANT FISH OBTAINED FROM WADI EL-RAYAN LAKE FOR HUMAN CONSUMPTION.

This study aims to evaluate the validity of some dominant fish obtained from Wadi El-Rayan lakes for human consumption and also to investigate the effect of common cooking methods (grilling and frying) on quality criteria, organochlorine (OC) pesticide residues and heavy metals. Nile tilapia (Oreochromisniloticus) and mullet (Mugilcephalus) (1st Lake) and red belly tilapia (Tilapia zillii) and mullet (Mugilcephalus) samples (2nd Lake) during winter 2015 were obtained. Results showed that ranges of quality criteria of raw fish samples were 11.35-12.75 mg/100g (total volatile basic nitrogen (TVBN), 0.48-0.80 mg MAD/kg as thiobarbituric acid (TBA) value and 2.15-2.50×103cfu/g total plate count (TPC). Organochlorine (OC) pesticide residues, average concentrations ranged between 0.017-0.103 ppm of ?DDT, 0.003-0.244 ppm of ? Endosulfan, 0.014-0.126 ppm of ? Cyclodienes and 0.021 – 0.065 ppm of ?HCH (?, ? and ?) in the investigated fishes. Heavy metals levels in raw fish samples ranged 0.196-0.456 Pb, UD-0.066 Cd, 0.052-0.226 Mn, 0.018-0.057Cu, and 0.086-0.538Zn (ppm, ww). With regard to the effect of cooking methods, all values of quality criteria, most OC varied as affected by cooking methods applied, location and fish species. Frying of fish was more effective in reduction of OC components than grilling. However, grilling was reduced all heavy metals values in investigated fish samples, while levels of heavy metals were fluctuated in fried products. In conclusion, quality criteria and pollutants; OCP and heave metals in raw and cooked fish were lower the maximum permissible limits (MPLs) and therefore these fishes are validating for human consumption.