Development and Validation of Thermal Surrogate Microorganisms in Ground Beef for In-Plant Critical Control Point Validation Studies

This study identified a non-pathogenic bacterium that has heat resistance properties similar to Listeria and Salmonella in meat and poultry. Research developed protocols for the use of a non-pathogenic surrogate organisms in processing facilities to validate thermal processing.

Download final report

Objectives

To compare the thermal inactivation relationships of Enterococcus faecium to those of Listeria monocytogenes and Salmonella in ground beef.

Conclusions

In ground beef containing 12% fat, L. monocytogenes was consistently more heat sensitive than S. Senftenberg at all four temperatures tested.  Also, results indicated that thermal treatments that kill E. faecium 2354 in ground beef would also kill L. monocytogenes and Salmonella.  In a search for a less heat resistant surrogate than E. faecium 2354, the heat resistance of Pediococcus parvulus HP and Pediococcus acidilactici LP, which are used as commercial meat starter cultures, were compared.   These two Pediococcus strains may be alternate surrogates for validation studies when a less heat resistant surrogate is desired; however, studies at additional temperatures are needed with these strains for validation of a temperature range of 58 to 68°C.

Deliverable

Depending on the margin of safety desired, processors could use E. faecium 2354 as a surrogate for validation studies of thermal processes for lean and 12% fat ground beef at 58 and 68°C.