ملخص
Tracking the Bacteriological Quality of Selected Species of Imported Frozen Fish within the Western Region of Libya Adel Mohamed Abu Zayd ElMarghani (Ms. Sci. Thesis). University of Tripoli (2017). Advisor. Dr. Nuri Sahli Madi (Professor). Abstract The aim of this study was to evaluate the bacteriological quality of four frozen fish species (164 samples), Sparus aurata, Scombers combrus, Coryphaenahippurus and Merluccius merluccius, collected from, Alsabaa region main freezing stores, Ghargour region main freezing stores and the retail stores. The results showed that the average Heterotrophic Plate Counts of the samples collected from Alsabaa, Ghargour and retail stores were 4x103 , 2x104 , and 5x103 CFU/g respectively. The average Coliform Bacteria Group Counts were <250 CFU/g in Alsabaa and Ghargour stores, while it reached 1x103 CFU/g in retail stores. Vibrio bacteria were recorded in 91% of the samples collected from Alsabaa stores, and from 78% of samples collected from both Ghargour and retail stores, while, Thermotolerant (faecal) Coliform Bacteria, Escherichia coli and Vibrio parahaemolyticus were not recorded in all studied samples. The average Heterotrophic Plate Count recorded in the pieces of Coryphaena fish was the highest (4x104 CFU/g), followed by 5x103 CFU/g in the whole Sparus samples, and 8x102 CFU/g in the whole Scomber samples, and 6x102 CFU/g in the Merluccius fillets samples. The average Coliform Bacteria Group Count in the samples was 2x103 CFU/g in the pieces of Coryphaena, while in the samples of the rest of the species it was <250 CFU/g. Vibrio bacteria were detected in 66, 74, 97, and 100% of the whole Scomber samples, whole Sparus, Merluccius fillets and pieces Coryphaena, respectively. The statistical analysis of the results indicated that there was no significant effect upon the differences in store location and the way of display for sale on Heterotrophic Plate Count and Coliform Bacteria Group Count, whereas the fish species had a significant effect on the Heterotrophic Plate Count, i.e. all species were better than the pieces of Coryphaena fish. However, whole Scomber fish, was significantly better than whole Sparus fish, followed by Merluccius fillets, and the pieces of Coryphaena fish in respect of the Coliform Bacteria Group Count. It was found that 98% of the samples were in accordance with the specific standards approved by the Libyan National Center for Standardization and Meteorology in terms of bacteriology. In spite of that, it is still necessary to apply sanitary requirements in frozen fish main stores and retailers, and implement a regular and periodic program to monitor their work system; all over Libya.