Principal Research Organisation: microbial ecology and physiology

Summary

This multi-faceted project commenced in September 2013 and was completed in April 2016.  The project focused on the microbial quality/shelf life and safety of vacuum-packed beef and lamb meat. The primary goal was to innovate in the areas of carcass safety, and shelf-life prediction and extension, and to develop new personnel with scientific expertise in these areas to support the Australian red meat industry.

The PROMEP project focused on the microbial quality/shelf life and safety of vacuum-packed beef and lamb meat. The primary goal was to innovate in the areas of carcass safety and shelf-life prediction and extension, and to develop new personnel with scientific expertise in these areas. PROMEP involved five sub-projects, which are briefly described below.

The work was needed because exports markets for Australian red meats were increasing their demands for demonstration that pathogenic E. coli are not present on red meat products. Associated with those expectations was the likely requirement for the implementation of "interventions", i.e., additional processes during meat processing that could reduce levels of pathogenic E. coli that may be present on carcases. From previous MLA-funded research there was evidence that air chilling can kill E. coli, i.e., such that chilling could be considered as an intervention. The benefits were expected to be enhanced public health, industry reputation and industry productivity by minimally expensive approaches to meet international standards.
Similarly, Australian vacuum-packaged meat primals are internationally recognised for an extended shelf-life. However, there was little science-based information to explain this advantage. Previous MLA-funded projects had measured changes in sensory and microbiological properties of vacuum-packaged beef primals from six Australian export abattoirs, showing significant differences in microbiological profiles.

These findings led to a second phase of research, indicating that differences in bacterial growth profiles and communities were more likely due to properties of specific bacterial strains. Subsequent research showed that bacterial strains from abattoirs with low growth were more sensitive to pH, lactic acid and to low concentrations of glucose. These abattoirs also had a higher proportion of strains that produced inhibitory compounds against other bacteria, with greatest effects against bacteria of the same species. It was proposed that such interactions might limit the overall growth of the bacterial community, resulting in longer shelf-life and a higher quality. The aim was to better understand the factors that control these strain interactions to explain how the structure of spoilage communities is formed and potentially exploit that understanding to further extend red meat shelf life.