Abstract Background: Whole muscle meat, meat products, and seafood contain different nutrients in adequate quantity providing a better environment for presence and replication of different microorganisms. There are underreported and inaccurate estimations of foodborne diseases due to the lack of effective surveillance systems in Libya. Aim: To determine the extent of microbiological contamination of whole muscle meat, meat products, and seafood. Methods: A total number of 731 samples of retail meat were collected from different stores in four cities in Libya. Samples were analyzed for aerobic plate count and subjected to microbiological enumeration and isolation techniques, followed by molecular identification by PCR and partial sequencing of 16S rDNA. Results: The results showed contamination of samples with enteric and spoilage bacteria. Fifteen genera of spoilage bacteria yielded 149 isolates which were detected and identified by PCR and partial sequencing of 16S rDNA as: Proteus spp., Provedencia spp., Raouttella ornithinolytical, Citrobacter spp., Enterobacter spp., Morganella morgi, Shewanella algea, Rhodobacter capsulatus, Listonella pelagia, Kluyvera spp., Pectobacterium spp., Brenneria spp., Klebsiella spp., Acintobacter radioresistens, and Pantoea spp. While for pathogenic bacteria, 143 isolates distributed among nine genera were identified by PCR and partial sequencing of 16S rDNA as: Bacillus spp., Escherichia spp., Shigella spp., Enterococci spp., Cronobacter spp., Staphylococci spp., Salmonella spp., Aeromonas spp., and Vibrio spp.. Many isolated bacteria are zoonotic bacteria with high importance for public health. Conclusion: Excessive handling and processing of meat and meat products seems to be one of the poorest microbiological qualities. These findings ought to be helpful in risk assessments and quality assurance of meat in order to improve food safety.
Hesham Taher Naas(9-2020)

The objective of this study was to evaluate the effect of nisin in combination with different types of packaging on the survival of Listeria monocytogenes in ready-to-eat low-fat turkey bologna. Bologna was inoculated with L. monocytogenes exposed to 1 of 6 treatments: 3 packaging treatments (100% CO2, air, vacuum), each with and without nisin. Bologna was refrigerated and sampled 9 times over 42 d. Nisin reduced initial L. monocytogenes populations by 1.5 to 2 log cycles and 100% CO2 packaging prevented outgrowth throughout 42 d of storage, whereas non-CO2 packaging displayed a 2-log increase in population during storage. Nisin (500 IU/mL) combined with 100% CO2 was effective in reducing Listeria and preventing outgrowth on bologna over 42 d of refrigerated storage.
Hesham Taher Naas(3-2013)

This study determined the efficacy of actinidin and papain on reducing Listeria monocytogenes and three mixed strains of Escherichia coli O157:H7 populations on beef. The average reduction of E. coli O157:H7 was greater than that of L. monocytogenes and higher concentrations of either protease yielded greater reduction in bacterial populations. For instance, actinidin at 700 mg/ml significantly (p ≤ 0.05) reduced the population of L. monocytogenes by 1.49 log cfu/ml meat rinse after 3 h at 25 & 35 °C, and by 1.45 log cfu/ml rinse after 24 h at 5 °C, while the same actinidin concentration significantly reduced the populations of three mixed strains of E. coli O157:H7 by 1.81 log cfu/ml rinse after 3 h at 25 & 35 °C, and 1.94 log cfu/ml rinse after 24 h at 5 °C. These findings suggest that, in addition to improving the sensory attributes of beef, proteolytic enzymes can enhance meat safety when stored at suitable temperatures.
Hesham Taher Naas(12-2013)