English abstract
The Central Slaughterhouse is the only slaughterhouse in Muscat area. In this study, possible sources of microbiological contamination onto carcasses in the Central Slaughterhouse were studied and a Hazard Analysis and Critical Control Point (HACCP) system was designed based on microbial observations. Microbiological profiles of two sites (brisket and dorsal) on the animal carcasses were determined, using both swabbing and sponge techniques, at different stages during slaughterhouse processing. Microbiological contamination of equipment, the environment and workers' hands and aprons was also evaluated. The mean count recovered by swabbing (logio 1.83 + 0.38 cfu.cm2) was significantly higher (P <0.05) than that obtained using the direct sponge technique (logio 1.31 0.38 cfu.cm?). The mean total bacterial count determined at 20 + 2°C was not significantly different from that obtained at 35 + 2°C. Salmonella spp., Staphylococcus aureus, Pseudomonas spp. and E. coli were all recovered from carcasses. The total bacterial count from aerosols did not vary significantly between different processing locations. However, when animals were present, the proportion of Gramnegative organisms increased dramatically. Results of a questionnaire demonstrated that most of the workers have low educational standards and very limited knowledge about food safety and hygiene. Also, sampling of workers' hands gave a 100% frequency of contamination with Staphylococci spp. This indicated a major role for workers in crosscontamination of carcasses. The cutting board surface was also identified as a major source of contamination. The average mesophilic bacterial count was log10 5.56 cfu.cm? and 50% of samples were Salmonella spp. and Staphylococci spp. positive. Penicillum spp. molds were recovered and even in some cases showed visible growth on the board. Microbial contamination of equipment was high, the mean total count (logio cfu /one side of blade) of knives were between <3.00 to 5.90 and <3.00 to 3.78 logio cfu.cm-for aprons. A HACCP plan was designed for the slaughterhouse based on the microbiological evaluation and the seven principles of HACCP. Three critical control points were identified as evisceration, inspection and chilling. Implementation of this plan will reduce the levels of microbial and physical contamination and imnrove the safety and shelf-life of the meat.
