Products used for testing included ready-to-eat frankfurters and boneless hams.

During the investigation of antimicrobial ingredients, researchers found that 1 percent cranberry powder did not inhibit growth over 98 days of refrigerated storage, compared to the initial levels. However, 1 percent vinegar and 2.5 percent vinegar and lemon concentrate did limit growth during refrigerated storage compared to initial levels. None of the ingredients caused initial Lm populations to decrease.

The investigated  post-lethality interventions, including high hydrostatic pressure (400 MPa for four min.), lauric arginate (44 ppm) and octanoic acid (400 ppm), decreased initial populations of Lm compared to the untreated control, but the populations were able to recover and showed growth by the end of the storage period.

Researchers concluded that only a combined approach using antimicrobial ingredients and post-lethality interventions could initially decrease and suspend the recovery of Lm populations.

CDC reports Listeriosis is a serious infection and important public health problem in the US caused by eating food contaminated with Listeria monocytogenes. The disease primarily affects older adults, pregnant women, newborns, and adults with weakened immune systems.

Symptoms include fever and muscle aches as well as problems in the gastrointestinal tract, although greater complications can arise. According to CDC, it’s estimated that 1600 illnesses and 260 deaths can be attributed to Listeriosis each year.

The full study can be found here.