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Application of Antimicrobial Treatments in a Commercial Simulation to Reduce E. coli O157:H7 and Salmonella spp. in Beef Trim and in Ground Beef


The digestive tracts of animals are natural reservoirs of foodborne pathogens including
Salmonella spp. and Escherichia coli O157:H7. The muscles of a healthy animal are essentially
sterile, but even under the most stringent conditions, they can become contaminated during the
slaughter process from the environment, hide or from direct contact with the intestinal tract
contents. This contamination can lead to human illness if the processor or end-users do not
appropriately handle the product. For processors that specialize in further fabrication, especially
grinding facilities, pathogens are of great concern for both safety and economic reasons.
Processors, including grinders, are responsible for conducting routine testing of products they
procure, and must recall any fresh product that tests positive for E. coli O157:H7. Currently,
there are very few safety interventions that can be applied to beef trimmings or ground beef. <P>
This study was designed to determine methods for effectively reducing E. coli O157:H7 and
Salmonella spp. in beef trim and ground beef. Previous research has demonstrated the
effectiveness of applying lactic acid and acidified sodium chlorite in reducing pathogen loads on
beef carcasses and to a limited extent, on beef trim. The Food and Drug Administration (FDA)
has recently approved the use of acidified sodium chlorite (ASC) as a food additive to reduce
pathogen loads on both pre-chill and post-chill meat and poultry products. The use of
antimicrobials on beef trim has not however, been extensively documented in peer-reviewed
research. <P>
The objectives of this study were to validate the effectiveness and application of acidified
sodium chlorite (1,000 parts per million, or ppm), acetic and lactic acids (2 percent and 5
percent) and sterile water in reducing Escherichia coli O157:H7 and Salmonella spp. on beef
trim prior to and after grinding in a simulated processing environment. The researchers also
determined the effect of the treatments on sensory quality and the biochemical composition of
ground beef.

More information

Findings: Results from this study indicate that all antimicrobial interventions, including sterile water, reduced pathogen loads (P < 0.05) for both Escherichia coli O157:H7 and Salmonella spp. in ground beef. The antimicrobial treatments of: sterile water, 5% lactic acid, 2% acetic acid, 5% acetic acid, and acidified sodium chlorite significantly reduced Escherichia coli O157:H7 (P < 0.05) in ground beef. The antimicrobial treatments of: acetic and lactic acids (2% and 5%), acidified sodium chlorite (1000 ppm), and sterile water significantly reduced pathogen loads of Salmonella spp. (P < 0.0001) in ground beef 6 and 24 h after processing. The triangle tests indicate panelist could not detect a difference between the control and treated samples. There were no significant color differences between control and treated samples. Color uniformity differences occurred for control, 2% acetic and lactic acid samples. Discoloration differences occurred for acidified sodium chlorite, 2 and 5% acetic acid samples. Browning of lean color occurred for acidified sodium chlorite and for 5% acetic acid. There were no CIE L*, a*, b*, C and H differences. Research from this present study indicates that industries can utilize antimicrobial interventions under commercially simulated conditions on beef trimmings to reduce pathogens in ground beef.

<P> For complete projects details, view the <a href="…; target="_blank">Project Summary. </a>

Brashears, Mindy; Brooks, Chance ; Miller, Mark
Texas Tech University
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