In-plant evaluation of a lactic acid treatment for reduction of bacteria on chilled beef carcasses

The effectiveness of a lactic acid treatment consisting of spraying a 4% L- lactic acid solution (55 degreesC at source) on chilled beef carcasses to r educe bacterial populations was tested in a commercial slaughter environmen t. All carcasses had been treated with a proprietary decontamination treatm ent composed of a hot water spray followed by a lactic acid spray prior to chilling. Bacterial groups used to indicate reductions included aerobic pla te count (APC), total coliform count, and Escherichia coil count, and sampl es were examined from the brisket, the clod, and the neck regions of 40 unt reated and 40 treated carcass sides. Depending on the carcass surface regio n, APCs were reduced by 3.0 to 3.3 log cycles. Log coliform and E. coli cou nts were consistently reduced to undetectable levels. The small reductions observed for coliforms are attributable to counts on untreated carcasses al ready being near the lower detection limit of the counting method. The perc entage of samples with detectable numbers of coliforms (positive samples) o n untreated carcasses ranged from 52.5 to 92.5%, while 0.0% of the samples collected from treated carcasses contained detectable coliforms. Percent E. coli-positive samples ranged from 7.5 to 30.0% on untreated carcasses and 0.0% after treatment of carcass sides. These results indicate that a hot la ctic acid spray with increased concentration and time of application may be effectively implemented for an additional decontamination treatment of chi lled beef carcasses prior to fabrication.