Evaluation of a Steam Pasteurization Process in a Commercial Beef Processing Facility

Abstract

The effectiveness of a steam pasteurization process for reducing naturally occurring bacterial populations on freshly slaughtered beef sides was evaluated in a large commercial facility. Over a period of 10 days, 140 randomly chosen beef sides were microbiologically analyzed. Each side was sampled immediately before, immediately after, and 24 h after steam pasteurization treatment. Total aerobic bacteria (APC), Escherichia coli (generic), coliform, and Enterobacteriaceae populations were enumerated. The process significantly (P ≤ 0.01) reduced mean APCs from 2.19 log CFU/cm2 before treatment to 0.84 log CFU/cm2 immediately after and 0.94 log CFU/cm2 24 h after treatment. Before pasteurization (8 s steam exposure), 16.4% of carcasses were positive for generic E. coli (level of 0.60 to 1.53 log CFU/cm2), 37.9% were positive for coliforms (level of 0.60 to 2.26 log CFU/cm2), and 46.4% were positive for Enterobacteriaceae (level of 0.60 to 2.25 log CFU/cm2). After pasteurization, 0% of carcasses were positive for E. coli, 1.4% were positive for coliforms (level of 0.60 to 1.53 log CFU/cm2), and 2.9% were positive for Enterobacteriaceae (level of 0.60 to 1.99 log CFU/cm2). Of the 140 carcasses evaluated, one carcass was positive for Salmonella spp. before treatment (0.7% incidence rate); all carcasses were negative after steam treatment. This study indicates that steam pasteurization is very effective in a commercial setting for reducing overall bacterial populations on freshly slaughtered beef carcasses. The system may effectively serve as an important critical control point for HACCP systems at the slaughter phase of beef processing. In conjunction with other antimicrobial interventions (mandated by USDA to achieve zero tolerance standards for visible contamination) and good manufacturing practices, this process can play an important role in reducing the risk of pathogenic bacteria in raw meat and meat products.

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.…”

Interventions to control Salmonella contamination during poultry, cattle and pig slaughter

“…low temperature, relative humidity, air speed and water activity (Nottingham, 1982) and even can cause stress and kill certain proportion of bacterial cells. The actual evidence as to whether such effects result in Salmonella reductions that are of significant practical relevance is limited and conflicting (Gill & Bryant, 1997;McEvoy et al, 2000;Nutsch et al, 1997). Results from some more recent studies suggested that as great as 4-log reduction of artificially inoculated Salmonella on beef can be achieved by slow-aging (21 days) dry chilling regime (Tittor et al, 2005) which is usually accompanied by higher weight loss and used only by small operators.…”

Assessment of the Microbial Level for Livestock Products in Retail Meat Shops Implementing HACCP System

“…HACCP systems should be based on microbiological data that allow for estimation of the numbers of indicator organisms on meat products at various processing stages (Gill, 2000). The current approach to assessing microbial contamination of meat carcass at slaughterhouses and meat processing plants is to collect samples by excising or swabbing (Nutsch et al ., 1997). For raw meat products, safety and quality can be estimated using indicator microorganisms, and by subsequently obtaining the total aerobic plate count (APC), coliform count (CC), and E. coli (ECC) count (Jay, 1992).…”