Effects of some cooking methods and some treatments on the concentrations of heavy metals in meats

Effects of some cooking methods and some treatments on the concentrations of heavy metals in meats The aim of current study was to estimate some heavy metals like Lead "Pb" ,Mercury "Hg" ,Cadmium "Cd" Nickel "Ni" ,Copper "Cu" and Cobalt "Co" in fresh meats (Btello "small veal", Kndoz "beef" and Danni "sheep" ) also to investigate the effects of some cooking methods boiling and frying on these selected heavy metals in fresh meats, finally to investigate the protective effect of soaking fresh meats precooking in natural foods (tomato juice, lemon juice, onion juice and yogurt) on these heavy metals. A total of 330 random samples were selected of fresh meats (btello, kndoz and danni ) from the local markets of some villages in Damietta governorate(El Sananya , El Basarta , EL Adlya, El Bustan and El Brashya) , 110 samples of each type of meats to evaluate their content of lead, mercury, cadmium, copper, nickel and cobalt. Where samples of each type were divided into eleven groups of equal numbers (10 samples) as follows: group 1 includes fresh samples without any treatment , groups 2 and 3 include samples treated by cooking methods (boiling and frying respectively). Groups 4,5,6 and 7 include samples which boiled and treated by soaking in 100% natural foods (tomato juice, lemon juice, onion juice and yogurt respectively) for two hours before boiling. Groups 8,9,10 and11 include samples which fried and treated by soaking in 100% natural foods (tomato juice, lemon juice, onion juice and yogurt respectively) for two hours before frying . The main results showed significant differences between fresh btello samples and other samples fresh kndoz and fresh danni in the concentrations of heavy metals Cd, Cu, Ni and the concentrations of pb, Hg in all samples were found negligible. This indicates that the investigated samples of fresh meats btello ,kndoz and danni are safe from lead and mercury. The obtained results were concluded that mostly the values of heavy metals in fresh meats samples were lower than recommended maximum acceptable levels and the concentration of Pb and Hg were not detectable. Results also declared that cooking methods had an important effect on these selected heavy metals concentrations. Boiling and frying of fresh meats caused significant decrease (p<0.05) in Cd concentrations comparing to the concentrations of fresh meats. However , frying of fresh meats declared Home Econ. J . Vol. 34, 2018 112 significant decrease (p<0.05) in Co concentrations comparing the concentrations of fresh meats . Moreover, the concentrations of Ni for all boiled meat samples and fried danni meat samples showed significantly decrease(p<0.05) compared to that of fresh meat samples while, fried btello and fried kndoz meat samples showed no significant differences in the Ni concentrations between these samples and that of fresh meats . Therefore, the results showed significant increase in Cu concentrations after boiling in btello ,kndoz and danni meats respectively while, the results also declared significant decrease(p<0.05) in Cu concentrations in fried btello and fried danni meat samples. In this study it was found that soaking fresh meats (btello ,kndoz and danni) precooking in natural foods (tomato juice ,lemon juice, onion juice and yogurt) reduced selected heavy metals Cd, Cu, Co and Ni. The present study recommends that fresh meats should be processed before cooking with the natural foods studied in order to reduce the contamination of heavy metals and overcome their health problems. ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ ــــــــــــــــــــــــــــــ