Reduction of Bacteria Attached to Meat Surfaces by Washing with Selected Compounds.

Beef muscle and fat tissue were inoculated with either Listeria monocytogenes , Salmonella typhimurium , Staphylococcus aureus , or Serratia marcescens and washed with various compounds. There were no significant (P>0.05) differences in detachment and/or destruction of bacteria from lean tissue with phosphate buffer, ethanol, and NaCl, with all of the reductions being <1 log cycle. NaOH and KOH were effective in removing bacteria from both fat and lean tissue, reducing the populations of S. typhimurium and S. marcescens on the tissue by as much as 4 log cycles. For all of the bacteria tested, there were significantly more (P<0.05) bacteria removed or destroyed from fat tissue than from lean tissue. There was no significant difference (P>0.05) between NaOH and KOH. Concentration (1%, 5%, and 10%) of the wash solution had a significant (P<0.05) effect on all four of the bacteria. D values were determined for the bacteria in the three concentrations of NaOH. The values ranged from a high of 41 sec for S. aureus in 1% to <1.2 sec for L. monocytogenes in 10% NaOH.