DETECTION OF PESTICIDE RESIDUES IN MILK AND SOME DAIRY PRODUCTS

The study were conducted to monitor and determine the presence organochlorine pesticide residues in raw buffalo’s milk and some milk products. The studied samples were collected from different regions, Sharkia Governorate, Egypt. The effect of heat treatment on pesticide residue in raw buffalo’s milk and butter was also studied. The results showed that the only detected organochlorine pesticide residues in all examined milk samples was p,p’-DDE. Resides of DDE detected in yoghurt were 2.7298±0.1126 ppb, with a mean value of 1.9161±0.0992 ppb., while no residues were detected in cottage cheese samples. The organochlorine pesticide residues detected in butter samples were lindane, heptachlor epoxide and p,p’-DDE with mean values of 7.428±1.667, 3.384±1.583 and 67.063±4.933 ppb on fat basis, respectively. Effect of common heat treatment on p,p’-DDE residues in raw buffalo’s milk treated by pasteurization, boiling and sterilization, were 2.509, 0.932 and 0.2599 ppb on milk basis, respectively with degradation percent of 22.13, 71.16 and 92.8% , respectively. Resides detected in butter samples after heating processing to produce ghee were lindane, heptachlor epoxide and p,p’-DDE with a mean concentration 2.948, 1.935 and 15.609 ppb on fat basis respectively with degradation percent of 79.1, 87.50 and 76.76 %, respectively. We can conclude from the study that, the sterilization of raw milk is the most effective method for reduction of pesticide residues. The butter processing by heat treatment produced ghee (Samna) with marked decrease in organochlorine residue content.