Use of Hot Water for Beef Carcass Decontamination

Abstract

Hot water treatment of beef carcass surfaces for reduction of Escherichia coli O157:H7, Salmonella typhimurium, and various indicator organisms was studied using a model carcass spray cabinet. Paired hot carcass surface regions with different external fat characteristics (inside round, outside round, brisket, flank, and clod) were removed from carcasses immediately after the slaughter and dressing process. All cuts were inoculated with bovine feces containing 10(6)/g each of rifampicin-resistant E. coli O157:H7 and S. typhimurium, or with uninoculated bovine feces. Surfaces then were exposed to a carcass water wash or a water wash followed by hot water spray (95 degrees C). Counts of rifampicin-resistant Salmonella and E. coli or aerobic plate count (APC) and coliform counts were conducted before and after each treatment. All treatments significantly reduced levels of pathogens from the initial inoculation level of 5.0 log(10) CFU/cm2. Treatments including hot water sprays provided mean reductions of initial counts for E. coli O157:H7 and S. typhimurium of 3.7 and 3.8 log, APC reductions of 2.9 log, and coliform and thermotolerant coliform count reductions of 3.3 log. The efficacy of hot water treatments was affected by the carcass surface region, but not by delaying the treatment (30 min) after contaminating the surface. Verification of efficacy of hot water interventions used as critical control points in a hazard analysis critical control point (HACCP) system may be possible using coliform counts.

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

“…Compared with the lactic acid wash, the hot water wash reduced APC by an additional 1.1 log CFU and EBC by an additional 1.7 log CFU. In previous studies of hot water washes of postevisceration carcasses and chilled beef, similar reductions have been obtained: 2.1 to 2.9 log CFU for APC (11,17) and 2.7 to 3.3 log CFU for coliforms (10, 11), a group that represents the majority of Enterobacteriaceae on carcass surfaces (9).…”

“…The surface temperature of 70ЊC resulted in a 2.0-log reduction in APC and a 2.7-log reduction of coliforms (19). The surface temperature of 82ЊC resulted in a 4-to 4.9-log reduction of bacteria (11). The hot water wash cabinet used for preevisceration carcasses in our experiments applied 74ЊC water for 5.5 s. This treatment raised the carcass surface temperature to 70ЊC for 3.5 s and reduced both APC and EBC by 2.7 log CFU/100 cm 2 .…”

Geraniol-Loaded Polymeric Nanoparticles Inhibit Enteric Pathogens on Spinach during Posttreatment Refrigerated and Temperature Abuse Storage

“…Colonies of pathogens were differentially counted after 24 h incubation at 35°C. Salmonella enterica colonies are distinguished from E. coli O157:H7 colonies through appearance of blackened centers resulting from sulfite reduction, as well as through E. coli fermentation of lactose, producing yellow-tinted haloes (Castillo et al, 1998).…”

STEC in the beef chain: One health approach

“…Decontamination treatments of hides (Castillo et al, 1998a;1998b;McEvoy et al, 2001;Bosilevac et al, 2005) and dressed carcasses (e.g. steam vacuuming, steam pasteurization, hot water washes, organic acid washes, etc.)…”

“…Hot water (74-80ºC) 3.7 log reduction Castillo et al 1998b Steam pasteurization (above atmospheric pressure) 3.7 to 4.4 reduction Phebus et al 1997 assessors and risk managers need to ensure any such substance is fi rst shown to be safe and effective at signifi cantly reducing microbial contamination before it can be approved. In addition, EU authorities (e.g.…”