الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 151 |  |  |
| | | from | 151 | | |
Abstract
Chicken is one of the most important protein sources among the food products of animal origin because of higher nutritive value, less content of fat and the lower cost of production. Antimicrobials mainly used in chicken production either for disease treatment, prevention or growth promotion cause a highly risk. In Egypt, veterinary antibiotics are on the head of poultry production contaminants whereas the risk of veterinary antibiotics used haven’t controlled yet. Despite using antibiotics as growth promoters in Egypt as a developing country, there is a shortage in studies concerning gentamicin and ciprofloxacin residues in chicken meat. This study aimed to evaluate the residues of two of the most commonly used antibiotics in the poultry farms as well as, to study the effect of cooking and freezing on their residues.
Part Ι
A total of 120 chicken samples (60 baladi and 60broiler) chicken meat (breast and thigh) and liver samples were collected from poultry shops at Fayoum Governorate, Egypt. All samples were examined for presence of antibiotic residues using microbiological inhibition assay technique. The results of microbiological inhibition assay revealed that the highest mean of inhibition zone (I.Z) was recorded in liver, thigh and breast. Liver samples I.Z was significant (P<0.05) all over the examined samples.
The incidence of ciprofloxacin residues detected in all liver samples of both baladi and broiler chicken samples while breast and thigh muscle results were variable. All baladi chicken liver samples (100%) had ciprofloxacin residue with a mean average of 0.38 ± 0.039μg/g. Thirteen out of 20 thigh samples (65%) had ciprofloxacin residues with a mean average of 0.155 ± 0.029μg/g. Whereas in breast samples 13 out of 20 samples (65%) had ciprofloxacin residues with a mean average of 0.082 ± 0.025 μg/g. All broiler chicken liver samples (100%) had ciprofloxacin residues with a mean average of 0.47 ± 0.04μg/g. Fourteen out of 20 thigh samples (70%) had ciprofloxacin residues with a mean average of 0.16 ± 0.03μg/g. Whereas in breast samples 13 out of 20 samples (65%) had ciprofloxacin residues with a mean average of 0.09 ± 0.03μg/g.
Regarding gentamicin residues, most of baladi chicken liver samples (95%) had gentamicin residues with a mean average of 0.24 ± 0.027μg/g. In thigh muscle samples, 7 out of 20 thigh samples (35%) had gentamicin residues with a mean value of 0.03 ± 0.01 μg/g whereas in breast samples 6 out of 20 samples (30%) had gentamicin residues with a mean average 0.029 ± 0.01μg/g.
Ninety-five percent broiler chicken liver samples (95%) had gentamicin residues with a mean average of 0.366 ± 0.04 μg/g. Fourteen out of 20 thigh samples (70%) had gentamicin residues, with a mean average 0.08 ± 0.017 whereas in breast samples 13 out of 20 samples (65%) had gentamicin residues with a mean average of 0.07 ± 0.017μg/g.
The liver had the highest residual concentration level of ciprofloxacin and gentamicin residues, whereas the breast and thigh muscles had the lowest concentrations. Ciprofloxacin and gentamicin were validated according to the guidelines laid down by the National organization of Food Safety Authority (2020) that established the (MRL) of ciprofloxacin in chicken tissues as 0.2 μg/g in muscles, 0.4μg/g in liver; while MRL of gentamicin is 0.6μg/g for both liver and muscles. The study showed the presence of ciprofloxacin residues above the maximum residual limits (MRLs) by 65, 60 and 20% in baladi liver, thigh and breast respectively while, in broiler samples ciprofloxacin residues were above the maximum residual limits (MRLs) by 70%, 60%, and35%. in liver, thigh and breast respectively. Gentamicin residues in all baladi samples were within the MRL while, in broiler samples 10% of liver, samples were above the MRL while, thigh and breast muscle samples were within the permissible limit. Broiler chicken meat had higher residual level of ciprofloxacin and gentamicin more than baladi chicken meat.
Calculating estimated daily intakes (EDIs) by (µg/kg/day) and hazard index for ciprofloxacin and gentamicin residues based on the integration of data from analysis of antibiotics, chicken consumption rates and body weight of Egyptian adults which was estimated at 70 kg. The result revealed that EDI for ciprofloxacin residues were 0.148, 0.183 in liver, 0.032, 0.035 in breast and 0.060, 0.060 μg.kg-1body weight in thigh muscle samples of baladi and broiler chicken respectively. The hazard index (HI) were 0.02, 0.004 and 0.008 for liver, breast and thigh muscle samples of baladi chicken respectively, while the hazard index (HI) were0.025, 0.005 and 0.008 for liver, breast and thigh samples of broiler chicken respectively. The EDI for gentamicin residues were 0.093, 0.14 in liver, 0.011, 0.027in breast and 0.011, 0.031μg.kg-1body weight in thigh muscle samples of baladi and broiler chicken respectively. The estimated daily intakes in baladi and broiler chicken were within the acceptable daily intake (ADI) for ciprofloxacin and gentamicin residues. The hazard index (HI) for gentamicin were 0.004, 0.0005 and 0.0005for liver, breast and thigh muscle samples of baladi chicken respectively, while the hazard index (HI) was 0.007, 0.001and 0.0015for liver, breast and thigh muscle samples of broiler chicken respectively.
Part Π
Chicken fillet samples obtained from local market which was measured to confirm that no antibiotics were presented. The chicken sample was cut and homogenized using food blender. The homogenized sample (two kilos) was divided into 2 groups (one kilo each). One group was spiked with 250 ml of ciprofloxacin 20% and the second one was spiked with 250 ml of gentamicin sulfate 10%. Each group was divided into 10 samples (100g each). Each sample was subdivided into 5 groups (20g each) .The first group was cooked by boiling, the second by microwaving, the third was frozen at -18 ºC for one month, the fourth stored frozen for 2 months at-18 ºC and the last group was left raw (control).
Cooking by boiling 15-20 minutes resulted in considerable reductions in ciprofloxacin and gentamicin residues, with reduction percentages of 58.4%, 29.1%, respectively also ciprofloxacin and gentamicin were detected in broth of cooked meat samples. The result revealed that cooking by microwaving under full power at 800W, 2450 MHz with 1 spoonful of sunflower oil for 1 minute induce a remarkable reduction on ciprofloxacin and gentamicin residues with a reduction percentages reaching 91.4 % and 85% respectively. Ciprofloxacin residues degraded to their metabolites by freezing process at -18ºC for one month by 45.1% and for 2 months by75.1% in examined chicken samples. Storage of the chicken meat at -18 ºC for one month could reduce the concentration of gentamicin residues with mean value of 4.32±0.20 μg/g and reduction percentage of 46.8%. It worth to be noted that increase period of storage to two months freezing at -18 ºC could increase the percentage of reduction reaching 80.0% with an average mean of 1.62±0.20 μg/g.