Comparison of Methods for Decontamination from Beef Carcass Surfaces

Abstract

Methods for the removal of fecal contamination from beef carcass surfaces were evaluated using a fecal suspension containing a rifampicin-resistant strain of either Escherichia coli O157:H7 or Salmonella typhimurium. Paired cuts from four distinct beef carcass regions (inside round, outside round, brisket, and clod) were removed from hot carcasses after splitting, and subcutaneous fat and lean carcass surfaces from these cuts were used to model decontamination of prechilled carcass surface regions. Hot carcass surface regions were contaminated with an inoculated fecal suspension in a 400-cm2 area and then treated by one of four treatments either immediately or 20 to 30 min after contamination. One paired contaminated surface region from each carcass side was trimmed of all visible fecal contamination. The remaining paired carcass surface region was washed either with water (35°C) or with water followed by a 2% lactic or acetic acid spray (55°C). Surface samples were obtained for microbiological examination before and after treatment from within and outside the defined area contaminated with the fecal suspension. All treatments significantly reduced levels of pathogens; however, decontamination was significantly affected by carcass surface region. The inside round region was the most difficult carcass surface to decontaminate, regardless of treatment. Washing followed by organic acid treatment performed better than trimming or washing alone on all carcass region surfaces except the inside round, where organic acid treatments and trimming performed equally well. Overall, lactic acid reduced levels of E. coli O157:H7 significantly better than acetic acid; however, differences between the abilities of the acids to reduce Salmonella were less pronounced. All treatments caused minimal spread of pathogens outside the initial area of fecal contamination, and recovery after spreading was reduced by organic acid treatments.

Antibacterial activity of decontamination treatments for cattle hides and beef carcasses

“…Increasing the water temperature from 35 °C to 74 °C thereby increased the reductions obtained for aerobic bacteria and E. coli by about one order of magnitude (Gorman et al, 1995b). Compared to single water spraying, the combination treatment increased the reductions obtained for E. coli O157:H7 and S. Typhimurium by 0.2-0.4 and 1.0-1.9 log CFU cm -2 , respectively (Hardin et al, 1995). Water spraying followed by spraying with lactic acid (2%) reduced aerobic bacteria, coliforms, Enterobacteriaceae, E.…”

“…Reductions were thereby about one order of magnitude higher than those obtained for water spraying alone (Hardin et al, 1995). In the study of Castillo et al Furthermore, the combination of steam vacuuming with lactic acid spraying (2%) reduced aerobic bacteria, coliforms, Enterobacteriaceae and E. coli inoculated on beef carcass surface parts by 3.5-4.5 log CFU cm -2 (Table 6).…”

“…Depending on water temperature and application time, aerobic bacteria, coliforms, Enterobacteriaceae, E. coli, E. coli O157:H7, L. innocua and Salmonella (S. Typhimurium, S. Wentworth) were reduced by 0.2-3.4, 1.3-4.0, 1.7-3.8, 0.9-3.9, 1.7-4.0, 1.9-2.5 and 1.8-4.3 orders of magnitude, respectively (Bell, Cutter, & Sumner, 1997;Castillo, Lucia, Goodsen, Savell, & Acuff, 1998b;Castillo, Lucia, Goodsen, Savell, & Acuff, 1998c;Castillo, Lucia, Kemp, & Acuff, 1999b;Castillo, McKenzie, Lucia, & Acuff, 2003;Castillo et al, 2001b;Cutter, 1999;Dorsa, Cutter, & Siragusa, 1997b;Dorsa et al, 1996b;Gorman et al, 1995b;Hardin, Acuff, Lucia, Oman, & Savell, 1995;King et al, 2005). Reductions obtained under commercial conditions for aerobic bacteria, coliforms,…”

A Review on Some Organic Acids Additives as Shelf Life Extenders of Fresh Beef Cuts

“…However, the FSIS-USDA has currently approved the use of solutions of acetic, lactic and citric acids at concentrations of 1.5-2.5% [79] . There have been several studies investigating the use of organic acids as sanitizing solutions to improve shelf-life and safety of fresh meat [2,64,78,80] . In general, organic acid have been effective (1-3 log reductions in log mean bacterial counts) in reducing bacterial populations and presence of pathogens on carcasses [2,81] .…”

Impact of Inoculum Preparation and Storage Conditions on the Response of Escherichia coli O157:H7 Populations to Undercooking and Simulated Exposure to Gastric Fluid

“…Four rifampin-resistant (100 g/ml) derivatives of Escherichia coli O157:H7 (ATCC 43895, ATCC 43889, ATCC 51658, and EO139 [venison jerky isolate provided by M. P. Doyle, University of Georgia, Griffin]), developed in our laboratory according to procedures described by Hardin et al (14) were used in this study. Stock cultures of each strain were maintained at Ϫ70°C in TSB (Difco, Becton Dickinson Co., Sparks, MD) containing 100 g/ml of rifampin (Sigma Chemical Company, St. Louis, MO) and 20% glycerol (Mallinckrodt Baker, Inc., Paris, KY).…”