The effects of pre-and post-slaughter spray application with organic acids on microbial population reductions on beef carcasses

As an attempt to control bacterial cross-contamination of beef carcasses, in the present investigation acetic acid and lactic acid (3% v/v) were used for bacterial decontamination. For the decontamination, cows were sprayed with each above acid at two different stages; (i) on live animal's hides, (ii) on carcass surfaces immediately after slaughter. Microbiological samples were taken on different hide areas of animals before spraying and on carcass surfaces at 24h after spraying. Meat quality traits were also analyzed on the sprayed animals. The detected microorganisms were identified using 16SrRNA gene sequencing. A diversity of bacterial species such as Staphylococcus, Shigella, Bacillus, Escherichia and Salmonella etc. were found on both external hide and carcass surface samples. The decontamination sprays significantly reduced the numbers (2-5 log unit) of all aforementioned bacterial species on carcass surfaces as compared with non-sprayed control. Thus, the two times-spray applications with the acid could be an effective tool for reducing bacterial cross-contaminations of beef carcass without adverse effect on meat quality.