Steam Pasteurization of Commercially Slaughtered Beef Carcasses: Evaluation of Bacterial Populations at Five Anatomical Locations

Abstract

A steam pasteurization process (patent pending) has been shown to effectively reduce pathogenic bacterial populations on beef tissue and to significantly reduce naturally occurring bacterial populations on commercially slaughtered beef carcasses. The objective of this study was to determine the effectiveness of the steam pasteurization treatment for reducing bacterial populations at several anatomical locations on commerically slaughtered carcasses. Before and after pasteurization treatment (82.2 degrees C, 6.5-s exposure time), a sterile sponge was used to sample 300 cm2 at one of five locations (inside round, loin, midline, brisket, or neck). Eighty carcasses (40 before treatment and 40 after treatment) were sampled per anatomical location over 2 processing days. Before treatment, aerobic plate counts (APCs) were found to be highest (P < or = 0.01) at the midline (4.5 log10 CFU/100 cm2), intermediate at the inside round, brisket, and neck (ca. 3.8 log10 CFU/100 cm2), and lowest at the loin (3.4 log10 CFU/100 cm2). After treatment, APCs at all locations were reduced significantly (P < or = 0.01). The inside round, loin, and brisket had the lowest (P < or = 0.01) APCs (ca. 2.6 log10 CFU/100 cm2), whereas the midline and neck had APCs of 3.1 and 3.3 log10 CFU/100 cm2, respectively. The lower reduction in APCs at the neck area indicated that the treatment may not be as effective there, possibly because of the design of the pasteurization equipment. Generic Escherichia coli populations were low at all locations before treatment, with populations on 32% of all carcasses sampled being less than the detection limit of the study (5.0 CFU/100 cm2). After treatment, E. coli populations were significantly lower (P < or = 0.01) than populations before treatment and 85% of all carcasses sampled had E. coli populations below the detection limit. The maximum E. coli population detected after treatment was 25 CFU/100 cm2. For enteric bacterial populations, no differences were observed in the effectiveness of the treatment among the five carcass locations.

Effects of steam pasteurisation on Salmonella Typhimurium DT104 and Escherichia coli O157:H7 surface inoculated onto beef, pork and chicken

“…For example, Table 1 Estimates of R, B and A and of goodness of fit (% variance) for the negative exponential equation and standard deviation between replicates (SD R ) and between times (SD T ) after treatment for 6.0-8.0 s, the data of Nutsch et al (1997Nutsch et al ( , 1998 at steam/air temperatures of 92 and 82°C, show reductions of about 1.0-1.5 logs for TVCs. These reductions are in contrast to those of Minihan et al (2003) of only about 0.5 of a log or less after heating at 90°C for 10 s. This shows that the reductions obtained in different studies cannot be compared, because the recorded temperatures refer to different locations, either on the carcass surface or in the chamber i.e.…”

Antibacterial activity of decontamination treatments for cattle hides and beef carcasses

“…Critical for the second effect is the temperature actually achieved on carcasses. To ensure correct treatment of the entire surface, conditions should be continuously monitored (Nutsch et al, 1998).…”

On-line real time aid to the verification of CCP compliance in beef slaughter HACCP systems

“…Indeed, the uncertainty surrounding the ability of traditional carcass decontamination (trimming) to eVect carcass surface bacterial reduction has led to the development of a myriad of intervention systems such as steam vacuuming e.g. Vac-San (Gill & Bryant, 1997), steam pasteurisation (Nutsch et al, 1998), hot water washing (Gill, Bryant, & Bedard, 1999), carcass surface treatment with organic acids (Smulders & Greer, 1998), etc.…”