The effect of calcium oxide nanoparticles (CaO NPs) was investigated comparing it to effects of some natural spices, in the refrigerated chilled minced meat to improve its shelf life. Also, the in vitro antibacterial effect was evaluated against E.coli ATCC 8739 and Salmonella typhimurium using agar well
diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The results demonstrated that all treatments showed improved effects on pH, color and odor in contrast to control. CaO NPs and garlic powder had the best effect on the Aerobic plate count (APC) and yeast and mould count, while onion powder had the best effect on the Enterobacteriaceae count through the storage period. It was concluded that CaO NPs showed good antimicrobial activity and consequently had improved the shelf life when added to minced meat. Also, garlic powder and onion powder enhanced the shelf life. In addition, CaO NPs solution, sage, garlic and onion extracts demonstrated superior antibacterial effects against E.coli ATCC 8739 and Salmonella typhimurium than ginger extract. SO, CaO NPs can be added for meat products as a multifunctional food additive.