Practical Elimination of Raw Meat Microbiological Risk using Thermal Pasteurization, a Novel Meat-Safety-Driven Technology

Abstract

Although the safety of raw meat products has improved in recent decades, raw meat is still associated with a considerable incidence of foodborne illnesses and death. Standard raw meat antimicrobial interventions such as chemical sprays can reduce meat quality, and their effectiveness has plateaued. However, a new thermal pasteurization technology implementing direct steam injection into ground meat and subsequent chilling of the meat by expansion under vacuum has the potential to nearly eliminate pathogens in raw ground meat products while preserving the proteins in the raw state. An inoculation (Escherichia coli surrogates) study of a full-scale pilot pasteurization system demonstrated the effectiveness of pasteurization to significantly reduce illness-causing pathogens in raw ground beef. High-level (log 6.3 colony-forming units per gram [cfu/g]) inoculations were used to validate the minimum temperature required to achieve a 5 log microorganism reduction, and low-level (log 3.8 cfu/g) inoculations were used to validate the minimum temperature required to achieve a 3 log microorganism reduction. At both levels of inoculation, pasteurization achieved the targeted reduction in inoculated microorganism populations (mean ± SEM log microorganism reductions for high-level = log 5.8 ± 0.04 cfu/g, low-level = log 3.3 ± 0.03 cfu/g). Ground beef protein profile and color were studied to determine functional effects of the thermal pasteurization technology. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry revealed no significant changes in the protein profile (<i>P</i> &gt; 0.05). Colorimetric measurements revealed minor changes that were visually insignificant in the color profile of processed versus unprocessed ground beef. A consumer acceptance study found similar preferences for pasteurized ground beef products compared with retail-available ground beef products.