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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Meat Safety and Quality » Research » Publications at this Location » Publication #181768
Title: TREATMENTS USING HOT WATER INSTEAD OF LACTIC ACID REDUCE LEVELS OF AEROBIC BACTERIA AND ENTEROBACTERIACEAE AND REDUCE THE PREVALENCE OF ESCHERICHIA COLI O157:H7 ON PREEVISCERATION BEEF CARCASSES

Author
item Bosilevac, Joseph - Mick
item Nou, Xiangwu
item BARKOCY-GALLAGHER, GENEVIEVE - CDC
item Arthur, Terrance
item Koohmaraie, Mohammad

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2006
Publication Date: 8/20/2006
Citation: Bosilevac, J.M., Nou, X., Barkocy-Gallagher, G.A., Arthur, T.M., Koohmaraie, M. 2006. Treatments using hot water instead of lactic acid reduce levels of aerobic bacteria and Enterobacteriaceae and reduce the prevalence of Escherichia coli O157:H7 on preevisceration beef carcasses. Journal of Food Protection. 69(8):1808-1813.

Interpretive Summary: Techniques and effectiveness of whole beef carcass spray washing have continually improved over time. Washing has evolved from use of ambient temperature washes, to use of warm water washes, to use of antimicrobials, hot water, and steam. We have previously demonstrated that hot water washing and steam vacuuming are effective means to decontaminate beef carcasses. Lactic acid is an organic acid that is used to sanitize whole carcass sides after evisceration, and it has become the most commonly used organic acid in commercial beef processing. Many processors also use lactic acid washes on pre-evisceration carcasses, but hot water washes may be more effective. To determine this, we compared hot water, lactic acid, and hot water followed by lactic acid as pre-evisceration carcass washes. Hot water reduced both aerobic plate bacteria (APC) and Enterobacteriaceae (EBC) by 2.7 log. Lactic acid reduced APC by 1.6 log, and EBC by 1.0 log. When the two treatments were combined, APC were reduced by 2.2 log and EBC by 2.5 log. Hot water reduced the prevalence of the pathogen E. coli O157:H7 on the carcasses by 81%, while lactic acid reduced E. coli O157:H7 prevalence by 35%. Carcass washes using a combination of hot water followed by lactic acid produced a 79% reduction in E. coli O157:H7 prevalence, a result no greater than that produced when hot water was used alone. These results indicate that washes using hot water would be more beneficial than washes using lactic acid for decontamination of pre-evisceration beef carcasses.

Technical Abstract: The efficacy of whole carcass spray washing as a means of decontaminating beef carcasses has continually improved over time. Washing has evolved from use of ambient temperature washes, to use of warm water washes, to use of antimicrobials, hot water, and steam. We have previously demonstrated that hot water washing and steam vacuuming are effective carcass interventions. Numerous other studies have evaluated the efficacy of a variety of organic acids for sanitizing whole carcass sides after evisceration. Lactic acid has become the most commonly used organic acid in commercial practice, and many processors have implemented lactic acid washes on pre-evisceration carcasses as well. Because of the effectiveness of hot water, we evaluated its use compared to lactic acid as a pre-evisceration wash. Hot water reduced the levels of both APC and EBC by 2.7 log CFU/100 square cm. Lactic acid treatment reduced the levels of APC by 1.6 log CFU/100 square cm and of EBC by 1.0 log CFU/100 square cm. When the two treatments were combined, APC levels were reduced by 2.2 log CFU/100 square cm and EBC levels were reduced by 2.5 log CFU/100 square cm. Hot water reduced Escherichia coli O157:H7 prevalence by 81% and lactic acid reduced E. coli O157:H7 prevalence by 35%, while the combination of the two produced a 79% reduction in E. coli O157:H7, a result which was no greater than when hot water alone was used. Using hot water would be more beneficial than using lactic acid for decontamination of pre-evisceration beef carcasses, because the main effects of decontamination occurred with the use of hot water, and the reductions were not increased by lactic acid treatment alone or in combination with hot water.