الفهرس 
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Abstract
Summary
Technical progress, various industrial activities and using of Al containers, different manufacturing process, additives that may be added including salt resultant in a significance increase of heavy metals contamination in milk and milk products especially Pb, Cd and Al which have serious hazards on human health. Therefore, this study was carried out on a total of 90 samples of butter and canned ghee randomly collected from Assuit city including 30 samples each of imported and locally made butter and 15 samples each of imported and local canned ghee. All samples in addition to the blank were analyzed for detection and/or measurement of Pb, Cd and Al by using of ZEEnit 700P Atomic Absorption Spectrophotometer with Graphite Furnace Unite (AASG).
Results revealed that mean values of Pb were 0.2909±0.0397, 0.5869±0.0868, 0.4542±0.0902 and 0.7674±0.0864ppm for imported butter, locally made butter, imported canned ghee and local canned ghee, respectively. While for Cd mean values were 0.00348±0.002, 0.00, 0.00 and 0.0134±0.0091ppm for the previous samples, respectively. But mean values of Al were not detected in all examined samples. Comparison of the concentration of these elements with the permissible limit was discussed.
The effect of adequate frying of some ghee samples in Al container on pb, Cd, Al concentration was studied. The results showed that mean concentration of Pb, Cd and Al before frying were 0.4266±0.1487, 0.0 and 0.0 ppm, respectively, while after frying their concentration increased to 2.2343±0.5726, 0.1566±0.0384 and 0.0006±0.00018 ppm, respectively.
The influence of milk processing on the fate of investigated elements showed that producing cream by centrifugation led to remove about 82.86%, 90.3% and 89.55% of Pb, Cd and Al, respectively in skim milk.
More over, churning process remove great portion of elements from butter, about 0, 20.38 and 78.86% of pb, Cd and Al, respectively were drown in butter milk. Consequently, the production of ghee from butter caused a reduction in the levels of pb, Cd and Al by 17.03, 3.07 and 28.15%, respectively than that found in butter which descend in morta.
It was concluded that conversion of milk into ghee caused nearly high reduction of metals in the end products that the level of pb, Cd and Al in ghee were 1.43, 5.23, 0%, respectively related to initial milk
During Kareish cheese manufacture, the produced Kareish cheese contains 45.26%, 18.64% and 71.36% of pb, Cd and Al, respectively.
It could be concluded that metals are released by more than 80% in to skim milk, with different distribution of metals between whey and Kareish cheese. Obviously there is reduction in fate of metals toward fat milk products especially ghee than toward Kareish cheese manufacturing, this may be due to salting during rennet production as it was noticed during examination of 10 random salt samples that mean values of Pb, Cd and Al were 6.2926±0.3304, 0.0009±0.0009 and 6.7700±6.7700 ppm, respectively, compared with their permissible limit. So must control rennet and salt before cheese manufacture.