Utilizing Predictive Modeling and Risk Assessment to Enhance Microbiological Safety of Meat
By Joyjit Saha and Divya Jaroni
Additionally, temperature abuse of contaminated ground beef during retail storage (> 5 °C) could also influence pathogen growth. To lower the risk of contamination and subsequent foodborne illnesses, some ground beef processors have started using beef trim-wash as an added intervention. Although conventional sanitizers, such as organic acids, are used as beef trim interventions, their efficacy at abuse temperatures is questionable, especially during longer retail storage. It is important to find alternatives that would maintain effectiveness throughout retail storage. Bacteriophages, known for enhanced activity at higher temperatures, could serve as alternatives for beef trim interventions. However, it is not certain if this would help reduce the risk significantly enough to be worth the cost. It is therefore important to understand the effectiveness of any intervention prior to actual implementation. Quantitative microbial risk assessment (QMRA), which assesses the risk of foodborne illness from current production practices and predicts the effectiveness of proposed
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interventions, could help processors make an informed decision. At the same time, it could also be used as a decision-making tool to select interventions without the hassle of actual implementation, which would be more economical and efficient. This would help processors make an informed decision before choosing an intervention. Currently, I am working on finishing my dissertation project which looks at the application of bacteriophages as beef trim intervention to control STEC in ground beef. Apart from my dissertation project, I worked on several additional projects during my degree. These projects include assessment of risk factors associated with the occurrence of STEC on smallscale cow-calf operations in Oklahoma and Louisiana, isolation and characterization of bacteriophages, accelerated survival and shelf life modeling of phages, cooking validation
studies for mechanically tenderized steaks, and looking at various antimicrobials for their potential for biofilm disruption. Among these projects, prediction of the safe cooking time of mechanically tenderized beef steaks got the most attention from both the industry and American Meat Science Association (AMSA). Mechanical tenderization is an integral part of commercial meat processing in the U.S. It involves piercing of the intact meat with needles/small blades and ensures consistency in the tenderness of resulting products. According to a 2004 nationwide retail survey, 45% of the retail meat was labeled as moisture-enhanced or mechanically tenderized. The popularity of tenderized poultry and meat products, however, has also been accompanied by serious food safety concerns. The technique of blade/needle-piercing could lead to the increased transfer of
IMAGES / JOYJIT SAHA & DIVYA JARONI
In the past two decades, Shigatoxigenic Escherichia coli (STEC) has been identified as the causative agent in numerous foodborne illness outbreaks linked to beef products, particularly ground beef. As part of the commensal microflora of cattle, STEC could easily contaminate beef carcasses, despite several antimicrobial treatments at various production and processing levels. Beef carcass trims used primarily in ground beef processing, which involves grinding and packaging of these trims, could result in increased risk of pathogenic contamination.
