Purpose: This in-plant validation study was conducted to determine the antimicrobial efficacy of lactic acid (2% to 5%) on indicator populations on cold beef carcasses, beef subprimals, and beef trim.
Methods: For each portion of the study (carcasses, subprimals and trim), 15 swab samples were collected before treatment and 15 samples were collected after treatment 3 times per day (beginning, middle and end of shift) A total of 180 samples for each product type were collected over two days. The swabs were then enumerated using petrifilms to determine aerobic plate counts (APC), coliform and generic E. coli (EC) populations per swab area. Reductions for each population were determined by comparing before and after treatment samples with an α-value of 0.1.
Results: Aerobic plate counts were significantly (P < 0.0001) reduced for those carcasses treated with lactic acid. Additionally, for subprimals, the intervention significantly reduced APC (P = 0.046) and coliforms (P = 0.0197) in the treated surfaces. When individual subprimal components were compared, APC populations for clods and top butts were significantly lower after lactic acid treatment. Coliform counts were also significantly reduced for clods, top butts and knuckles. No significant (P > 0.1) were noted for beef trim.
Significance: These data indicate that a lactic acid spray of 2% to 5% is effective in reducing indicator organisms commonly used by the industry to assess process control, thereby improving the safety of the product. This antimicrobial intervention can be applied to multiple product points within the beef processing facility.