Success case: LAE® activity vs. Listeria monocytogenes
It has been proved that LAE® is active against L. monocytogenes in several tests as well as in its application in continuous production processes.
In vitro activity
LAE® Minimum Inhibitory Concentration (MIC) in vitro against L. monocytogenes is:
| µg/mL | |
|---|---|
| Listeria monocytogenes B4/97 | 8 |
| Listeria monocytogenes ATCC 15313 | 32 |
Inoculation and superficial application
In heat-treated meat products, LAE® application as a superficial treatment reduces L. monocytogenes viability.
Result table – Inoculation
Luchansky et al. proved that the superficial application of 30 mg/kg of LAE® in 1,5 kg of ham before being vacum packed reduced L. monocytogenes incidence in 6,5 log ufc/piece in inoculated samples with 7,0 log ufc/piece. And in the case of inoculated samples with 3,0 log ufc/piece of L. monocytogenes, the application of 30 mg/kg of LAE® reduced its presence below the detection limit (1,48 log ufc/piece) during 60 days at 4 ºC.
| Ham Inoculation with 7,0 log ufc/piece | Control | LAE® at 30 mg/kg | Reduction caused by LAE® at 30 mg/kg |
|---|---|---|---|
| 1 day at 4 ºC | 6,9 log ufc/piece | <1,48 log ufc/piece | >5,42 log ufc/piece |
| Ham Inoculation with 3,0 log ufc/piece | Control | LAE®at 30 mg/kg | Redution caused by LAE® at 30 mg/kg |
|---|---|---|---|
| 1 day at 4 ºC | 3,4 log ufc/piece | <1,48 log ufc/piece | >1,92 log ufc/piece |
| 60 days at 4 ºC | 4,7 log ufc/piece | <1,48 log ufc/piece | >3,22 log ufc/piece |
Result table – Superficial application
The ABC Research (USA) laboratory has carried out tests in different sliced cooked ham products and sliced smoked turkey, applying LAE® superficially at approximately 160 mg/kg resulting in a noticeable initial reduction of L. monocytogenes of 1,63 log ufc/g and >1,94 log ufc/g respectively.
| Initial counting | Control | LAE® at 200 mg/Kg | Redution caused by LAE® at 200 mg/Kg |
|---|---|---|---|
| Sliced cooked ham | 3,67 log ufc/g | 2,04 log ufc/g | 1,63 log ufc/g |
| Sliced smoked turkey | 3,04 log ufc/g | <1,10 log ufc/g | >1,94 log ufc/g |
Stopforth et al. indicated that the superficial application of 70 mg/kg of LAE® in 70 g ham cooked slices inoculated with 3,3 log ufc/g of L. monocytogenes, reduces to 1 log ufc/g L. monocytogenes presence.
