Comparison of Steam Pasteurization and Other Methods for Reduction of Pathogens on Surfaces of Freshly Slaughtered Beef

Abstract

The effectiveness of a recently invented “steam pasteurization” (S) process in reducing pathogenic bacterial populations on surfaces of freshly slaughtered beef was determined and compared with that of other standard commercial methods including knife trimming (T), water washing (35°C; W), hot water/steam vacuum spot cleaning (V), and spraying with 2% vol/vol lactic acid (54°C, pH 2.25; L). These decontamination treatments were tested individually and in combinations. Cutaneus trunci muscles from freshly slaughtered steers were inoculated with feces containing Listeria monocytogenes Scott A, Escherichia coli OI57:H7, and Salmonella typhimurium over a predesignated meat surface area, resulting in initial populations of ca. 5 log CFU/cm2 of each pathogen. Tissue samples were excised from each portion before and after decontamination treatments, and mean population reductions were determined. Treatment combinations evaluated were the following (treatment designations within the abbreviations indicate the order of application): TW, TWS, WS, VW, VWS, TWLS, and VWLS. These combinations resulted in reductions ranging from 3.5 to 5.3 log CFU/cm2 in all three pathogen populations. The TW, TWS, WS, TWLS, and VWLS combinations were equally effective (P > 0.05), resulting in reductions ranging from 4.2 to 5.3 log CFU/cm2. When used individually, T, V, and S resulted in pathogen reductions ranging from 2.5 to 3.7 log CFU/cm2 Steam pasteurization consistently provided numerically greater pathogen reductions than T or V. Treatments T, V, and S were all more effective than W (which gave a reduction on the order of 1.0 log CFU/cm2). Steam pasteurization is an effective method for reducing pathogenic bacterial populations on surfaces of freshly slaughtered beef, with multiple decontamination procedures providing greatest overall reductions.

Transportation and Lairage Environment Effects on Prevalence, Numbers, and Diversity of Escherichia coli O157:H7 on Hides and Carcasses of Beef Cattle at Processing

“…Multiple hurdle postharvest interventions have been very effective in eliminating carcass contamination (1,11,21). However, to maintain process control, the amount of contamination coming into the plant, as determined either by prevalence or counts, must be kept below a defined limit.…”

Antibacterial activity of decontamination treatments for cattle hides and beef carcasses

“…In another study, the use of the Vac-San ® system at different slaughter process stages and carcass areas reduced aerobic bacteria, coliforms and E. coli by 0.2-0.8 orders of magnitude (Gill and Bryant, 1997b). On the other hand, under laboratory conditions, steam vacuuming reduced several bacterial species on beef carcass surface parts by 1.6-5.5 orders of magnitude (Castillo, Lucia, Goodsen, Savell, & Acuff, 1999a;Dorsa, Cutter, & Siragusa, 1996a;Dorsa et al, 1996b;Dorsa et al, 1997b;Phebus et al, 1997).…”

“…However, supplementary hot water spraying (95 °C) did not further enhance the efficacy (Castillo et al, 1999a). Besides, in the study of Phebus et al (1997) Occasionally, the antibacterial activity of water spraying in combination with chemicals as ASC, chlorine, H 2 O 2 , ozone, peroxyacetic acid, saponin, TSP or commercially available preparations was investigated on inoculated beef carcass surface parts (Cabedo et al, 1996;Castillo et al, 1999b;Castillo et al, 2003;Cutter, 1999;Gorman et al, 1995b;Marshall et al, 2005;Penney et al, 2007). The different chemicals were mainly investigated in only one single study and under laboratory conditions.…”

Escherichia coli O157 Prevalence and Enumeration of Aerobic Bacteria, Enterobacteriaceae, and Escherichia coli O157 at Various Steps in Commercial Beef Processing Plants

“…surface contamination on beef tissue than are individual interventions alone (8,20,24). Many commercial beef processing plants presently employ several interventions (i.e., trimming, steam vacuuming, steam pasteurization, water washes, and organic acid washes) in combination to achieve large reductions in carcass contamination in accordance with their individual HACCP plans (1).…”

“…† Names are necessary to report factually on available data; however, the U.S. Department of Agriculture neither guarantees nor warrants the standard of the product, and the use of the name by the U.S. Department of Agriculture implies no approval of the product to the exclusion of others that may also be suitable. ‡ Present address: Room 119, Veterinary Diagnostic Center, East Campus, University of Nebraska, Lincoln, NE 68583-0907, USA.surface contamination on beef tissue than are individual interventions alone (8,20,24). Many commercial beef processing plants presently employ several interventions (i.e., trimming, steam vacuuming, steam pasteurization, water washes, and organic acid washes) in combination to achieve large reductions in carcass contamination in accordance with their individual HACCP plans (1).…”