| Abstract: |
The present study was concerned with chemical and microbiological studies on Grey mullet, mullet, Tilapia and Silvercarp fishes cultured at EI-Tal, El-Hussania 1 and 2, and EL-Abbassa. These are considered the largest cultures in Sharkia and Ismailia Governorates, Egypt. Moreover, the study also wanted to detect the hazard, if any, of consuming such fish on public health. The results of the study can be summarized as follows. Drying loss, total solids, protein, oil and ash were very stable for the same species and little difference was observed. Amino acid composition of fishes from the various fish cultures showed some difference as measured by chemical score. Fish from El-Tal had chemical scores of 30.0 and 56.5 for Grey Mullet, Tilapia and Silvercarp, respectively. In the case of El-Hussania culture (1), the chemical score, values were 19.7, 33.3 and 21.4 for Grey mullet, mullet and Tilapia, respectively. Data showed that high chemical score values were obtained for Mullet and Tilapia fishes (59.3 and 17.6, respectively) for El-Hussania culture (2). Tilapia and Silvercarp fishes from ElAbbassa culture had chemical score values of 40.8 and 28.6, respectively. Palmitic, oleic, and myrsitic are the main fatty acids found in fish from various cultures. Lauric acid was not detected in most fish from various cultures and only 2.6, 1.2 and 1.1 \% were recorded for Grey mullet and Tilapia from EI-Tal and Silvercarp from El-Abbassa. The mercury and lead contents of fish from various fish cultures differed according to both fish variety and culture. El-Tal culture showed the lowest chemical score and the highest mercury and lead concentrations. T.M.A.N. and T.V.B.N contents ranged from 0.2 to 4.0 and 2.8 to 8.5 mg/100gm, respectively, and from one species to another. T.B A. contents ranged from 0.62 to 0.48 to 0.70 : 0.20 to 0.59 and from 0.25 to 0.48 unit/kg for fish from El-TaL, El-Hussania culture 1 and 2 and El-Abbassa culture, respectively. Microbiological evaluation of fish from various fish cultures showed that El-Hussania culture 2 had the lowest microbial concentrations (total count - 0.3 x 10(6) to 0.7 x 10(6) and coliform group = 0.02 x 10(6) to 0.08 x 10(6)), while Mullet and Tilapia from ElHussania culture 1 had the highest total bacterial count (131 x 10(6) and 195 x 10(6), respectively). Tilapia from EI-Tal culture showed the highest coliform group count (23.9 x 10(6)).
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