Purpose: Evaluate the efficacy of 1) electrostatically applied lauric arginate (LAE) on chilled beef carcasses, 2) LAE applied to subprimals prior to vacuum packaging, followed by a peroxyacetic acid (PAA) spray after bag opening, and 3) LAE spray onto beef trim prior to grinding for reducing STEC surrogates.
Methods: Four chilled carcass sides were inoculated with a 5-strain surrogate STEC cocktail (5 log CFU/cm2) and held (~1°C) for 12 h prior to applying 200 ml of 25% LAE solution electrostatically. Loins from these carcasses were treated with LAE (200 ppm/weight) or water using the Sprayed Lethality in Container (SLIC) method prior to vacuum packaging and storage at 4°C. Bags were opened and loins were sprayed with PAA (200 ppm; 45°C). Two trim batches from each carcass side were treated with LAE (200 ppm/weight; 1 min) or water in a tumbler and held for 24 h at 4°C prior to grinding. Ground portions were taken from each batch and held for 2 or 4 days at 4°C. STEC surrogate populations were enumerated after each processing phase or storage period.
Results: Surrogate populations were reduced (P ≤ 0.05) ~0.7 log CFU/cm2 on chilled carcass surfaces following the electrostatic LAE application. Reductions of ~1.0 log CFU/cm2 were observed on LAE treated loin samples after refrigerated holding, with no additional reductions from the PAA spray after bag opening. LAE-treated trim showed a ~0.6 log CFU/g surrogate reduction compared to no reduction for water treated controls.
Significance: Low-volume LAE electrostatic spray application to chilled carcass sides, followed by applications (200 ppm/meat weight) to chilled subprimals and trim/ground beef effectively reduced STEC surrogate populations and would offer processors an additional level of STEC control following primary hot carcasses interventions.