الفهرس 
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Abstract
A total of 200 random samples of imported frozen broiler chicken carcasses including; breast and thigh (100 samples / each) were collected from supermarkets at Alexandria province to assess their quality through chemical and microbiological analysis. Samples were transferred directly with a minimum of delay to the laboratory of Food Hygiene Department, Faculty of Veterinary Medicine, Alexandria University in an insulating refrigerated container under complete aseptic condition to avoid any changes in the quality of the sample.
The obtained results revealed that pH values of the examined breast samples of imported chicken ranged from 5.95 to 6.40 with mean value of 6.25±0.05 and it was 5.85 to 6.35 with mean value of 6.15 ± 0.03 for the examined thigh samples of imported chicken. Moreover, it was noticed that all of the examined samples were within the permissible limit (6.5) recommended by Egyptian Organization for Standardization.
Total Volatile Nitrogen as proteolytic index of spoilage was determined. It was found that TVN values for examined breast samples of imported chicken ranged from 4.3 to 9.55 with mean value of 7.55 ± 0.24 while for thigh samples, it ranged from 6.4 to 12.8 with mean value of 9.95 ± 0.29. Moreover, it was noticed that all of the examined samples were within the permissible limit (30 mg %) recommended by Egyptian Organization for Standardization.
Thiobarbituric Acid (TBA) (mg %) as lipolytic index of spoilage was estimated for imported chicken samples. It was found that TBA values for examined breast samples of imported chicken ranged from 0.07 to 0.18 with mean value of 0.13 ± 0.01 while it ranged from 0.09 to 0.25 with mean value of 0.18 ± 0.01. Moreover, it was noticed that all of the examined samples were within the permissible limit (0.9 mg %) recommended by Egyptian Organization for Standardization.
Finally, it was found that PV values for examined breast samples of imported chicken ranged from 0.15 to 0.29 with mean value of 0.22 ± 0.01 while it ranged from 0.19 to 0.39 with mean value of 0.28 ± 0.01. Moreover, it was noticed that all of the examined samples were within the permissible limit recommended by Egyptian Organization for Standardization.
APC for breast samples ranged from 2.9×104 to 1.7×106 CFU/g with mean value of 7.6×105 CFU/g. APC for thigh samples ranged from 3.2×104 to 4.1×107 CFU/g with mean value of 4.9×106 CFU/g. Statistical analysis clarified that there was non-significant difference between APC of breast and thigh samples of imported chicken. It was clear that mean value of APC of thigh samples was higher than that of breast samples.
Also, it was recorded that 21 and 23% of the examined samples of breast and thigh exceeding the permissible limit of the Egyptian Standards (>105 CFU/g), respectively. EC for breast samples ranged from 2.6×104 to 4.2×105 CFU/g with mean value of 1.6×105 CFU/g. EC for thigh samples ranged from 3.4×104 to 5.3×105 CFU/g with mean value of 3.6×105 CFU/g. Statistical analysis clarified that there was non-significant difference between EC of breast and thigh samples of imported chicken.
It was clear that mean value of EC of thigh samples was higher than that of breast samples. CC for breast samples ranged from 1.3×103 to 2.9×105 CFU/g with mean value of 6.4×104 CFU/g. CC for thigh samples ranged from 3.7×103 to 5.3×105 CFU/g with mean value of 3.7×104 CFU/g. Statistical analysis clarified that there was non-significant difference between CC of breast and thigh samples of imported chicken. All of the examined samples of chicken carcasses had CC exceeding the permissible limit. It was clear that mean value of CC of thigh samples was higher than that of breast samples.
Staphylococci count for breast samples ranged from 1.7×102 to 4.6×103 CFU/g with mean value of 6.3×102 CFU/g. Staphylococci count for thigh samples ranged from 2.6×102 to 4.9×103 CFU/g with mean value of 2.5×103 CFU/g. Statistical analysis clarified that there was non-significant difference between Staphylococci count of breast and thigh samples of imported chicken. All of the examined samples of chicken carcasses had Staphylococci count exceeding the permissible limit. It was clear that mean value of Staphylococci count of thigh samples was higher than that of breast samples.
Mould count for breast samples ranged from 2×10 to 1.4×103 CFU/g with mean value of 3.6×102 CFU/g. Mould count for thigh samples ranged from 7×10 to 5.1×103 CFU/g with mean value of 6.2×102 CFU/g. Statistical analysis clarified that there was non-significant difference between Mould count of breast and thigh samples of imported chicken. All of the examined samples of chicken carcasses had Mould count exceeding the permissible limit. It was clear that mean value of Mould count of thigh samples was higher than that of breast samples.
Yeast count for breast samples ranged from 5×10 to 5.3×103 CFU/g with mean value of 1.9×103 CFU/g. Yeast count for thigh samples ranged from 1.6×102 to 3.1×104 CFU/g with mean value of 8.9×103 CFU/g. Statistical analysis clarified that there was non-significant difference between Yeast count of breast and thigh samples of imported chicken. All of the examined samples of chicken carcasses had Yeast count exceeding the permissible limit. It was clear that mean value of Yeast count of thigh samples was higher than that of breast samples.
The incidence of E. coli was higher in the examined samples of thigh (43%) compared to that of breast (27%). Serotyping of the obtained isolates of Enteropathogenic E. coli from imported chicken carcasses revealed the detection of O26 (EPEC) serotype at the rate of 6 and 10 % from the examined samples of breast and thigh, respectively, O86 (EHEC) serotype at the rate of 4 and 8 % from the examined samples of breast and thigh, respectively, O119 (EPEC) serotype at the rate of 5 and 9 % from the examined samples of breast and thigh, respectively, O126 (EIEC) serotype at the rate of 8 and 7 % from the examined samples of breast and thigh, respectively and O124 (ETEC) serotype at the rate of 4 and 9 % from the examined samples of breast and thigh, respectively.
The incidence of Salmonellae was higher in the examined samples of thigh (20%) compared to that of breast (13%). Serotyping of the obtained isolates of Salmonellae from imported chicken carcasses revealed the detection of S. Enteritidis at the rate of 3 and 4 % from the examined samples of breast and thigh, respectively, S. Typhimurium at the rate of 4 and 5 % from the examined samples of breast and thigh, respectively and S. Haifa at the rate of 6 and 11 % from the examined samples of breast and thigh, respectively.
The incidence of C. jejuni was higher in the examined samples of thigh (18%) compared to that of breast (15%) and finally, tahe incidence of C. perfringens was higher in the examined samples of thigh (9%) compared to that of breast (7%).