الفهرس 
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Abstract
The present investigation aimed to study chemical specifications of some common oils from Egyptian markets in great Cairo. Also, monitoring the residues of organochlorine pesticides in collected samples of edible oils from same locations was done. The role of shallow and deep-frying on 180°C±5°C/7-12min of some common foods spiked with known amounts of OCP’s on pesticides degradation was also studied. Removal of OCP’s residues from contaminated oil by using activated charcoal was also investigated throughout the present study. The obtained results could be summarized in the followings:
1- Data indicated that the normal sunflower oil have the characteristics of acid value ( 0.19 mg/KOH) ,peroxide value ( 4.13 meq/kg) ,iodine value ( 124.13 g I2/100g) ,saponification value ( 183.9919 mg/KOH) ,esterification value ( 183.7919 mg/KOH).Shallow as well as deep-frying of tested sunflower oil resulted in increasing acid and peroxide values of fried potatoes, falafel and eggplant, while decreased iodine, saponification and esterification values.Deep-frying caused slightly more changes in these characteristics than shallow-frying.
2- The characteristics of normal corn oil were 0.40 mg/KOH, 2.43 meq/kg, 122.90 g I2/100g,190.1719mg/KOH, and 189.7719mg/KOH in case of acid, peroxide, iodine, saponification and esterification values, respectively. Frying processes as shallow or deep-frying were variously increased the acid and peroxide values, but decreased the values of iodine, saponification and esterification compared with non fried oil samples.
3-Data indicated that the characteristics of normal palm olein oil were 0.30mg/KOH(acid value) , 5.06 meq/kg ( peroxide value) , 58.79 g I2/100g ( iodine value) , 197.35 mg/KOH (saponification value) and 147.05 mg/KOH (esterification value). Frying processes caused increasing effect on acid and peroxide values of oils , while the contrary was occurred with iodine , saponification and esterification values than non fried oil samples.
4- Subsidized (mixed) oil showed the characteristics of 0.50 mg/KOH , 4.37 meq/kg , 130.45 g I2/100g , 182.41 mg/KOH and 181.91 mg/KOH in case of acid , peroxide , iodine , saponification and esterification values ,respectively. Frying processes as shallow or deep-frying for common foods resulted in increasing acid and peroxide values of subsidized (mixed) oil, while decreased the values of iodine, saponification and esterification when used with potatoes, falafel and eggplant. Deep-frying caused in general slight more changes in these characteristics than shallow-frying.
5- Concerning the oxidative stability of sunflower oil , corn oil by rancimat at 100˚C , data indicated decreasing effect of frying processes as shallow or deep-frying on the induction period of the studied oils , but in various values due to oil type as well as type of frying process of potatoes , falafel and eggplant. The same trend was obtained with palm olein oil and subsidized (mixed) oil.
6- Data indicated that the majority of analyzed oil samples which were collected from Cairo governorate were found free from organochlorine pesticide residues. The positive oil samples which contained traces of OCP’s residues reached 4.29, 5.00, 6.43 and 13.57% as total in case of sunflower oil, palm olein oil, corn oil and subsidized (mixed) oil, respectively.
7- Frying processes and activated charcoal proved great role in reducing OCP’s residues from corn oil used with potatoes , falafel and eggplant. Deep-frying proved the best process used with eggplant. The loss percent in pesticide residues in contaminated oil without using in frying ,reached 89.20% , 71.25% , 77.50% and 88.00% in case of -BHC (gamma benzene hexachloride) , heptachlor epoxide , endrin and p,p’-DDE{1,1’-(2,2-dichloroethenylidene)-bis(4-chlorobenzene)},respectively.