Acetic Acid Spray Ineffective on Beef Carcasses With Low Bacteria Counts

Abstract

Bactericidal applications to meat carcass surfaces during processing are being considered as potentially beneficial interventions to reduce pathogen contamination and extend shelf-life. The efficacy of dilute (10 mL/L) aqueous acetic acid spray treatments of commercially processed beef carcasses, over a 61-week period was determined. Beef carcasses in two commercial processing plants were sprayed twice with dilute aqueous acetic acid, directly after hide and head removal, and subsequently after final carcass wash just prior to chilling. Two control plants did not use acid spray intervention. Carcass surface tissue samples were excised for bacterial analysis directly before chilling split carcasses. Samples were analysed for counts of total aerobic bacteria, lactic acid bacteria, total coliforms, and fecal streptococcus, and incidence of Salmonellasp. and Listeria monocytogenes. Counts were notably low and not meaningfully different between treatments. Incidence of Listeria monocytogeneson carcasses in plants using acid intervention was significantly ( P<0.05) higher than in plants not using acid spray. Salmonellae were not detected on any carcass surface tissue samples. This processing intervention was ineffective in lowering carcass bacteria counts and incidence of pathogens below those of control beef processing plants averaging low levels (less than log 10=4) of bacterial contamination without intervention.