|Campano, Stephen - Hawkins, Inc|
|Israeli, David - Mrs Ressler’s Food Products|
|Oser, Alan - Food Safety Connect, Llc|
Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2015
Publication Date: 5/1/2015
Citation: Porto Fett, A.C., Campano, S.G., Shoyer, B.A., Israeli, D., Oser, A., Luchansky, J.B. 2015. Comparative Efficacy of Potassium Levulinate with/without Potassium Diacetate and Potassium Propionate vs Potassium Lactate and Sodium Diacetate for Control of Listeria monocytogenes on commercially prepared uncured t.breast. Journal of Food Protection. 78:927-933.
Interpretive Summary: The majority of sporadic listeriosis cases are associated with consumption of ready-to-eat (RTE) deli meat and poultry products contaminated with Listeria monocytogenes. This life-threatening foodborne pathogen can grow at refrigeration temperatures and thus increase in numbers during extended cold storage. Its association with RTE deli meats is of particular concern because these products are stored at refrigeration temperatures for extended times and also because RTE meats are primarily consumed without further heating. Thus, we evaluated the ability of food grade antimicrobials to inhibit L. monocytogenes on commercially-prepared, uncured turkey breast because such products have caused listeriosis in the recent past. We evaluated the behavior of L. monocytogenes (about 1,000 cells per slice) on the surface of uncured turkey breast formulated with and without food grade salts of potassium levulinate and/or potassium propionate-diacetate during storage at refrigeration temperature. When product was formulated without these antimicrobials, pathogen numbers increased to about 100 million cells per slice after 90 days. However, when lower concentrations of levulinate were added to the formulation, pathogen numbers increased to about 1 million cells per slice after 90 days, whereas when levulinate was used at higher concentrations, growth of the pathogen was inhibited throughout storage. In addition, regardless of the concentration, when levulinate was used in combination with propionate-diacetate, pathogen growth was inhibited over 90 days of refrigerated storage. These data confirm that in an event of post-process contamination, levulinate, alone or in combination with propionate-diacetate, would be effective formulation ingredients for inhibiting outgrowth of L. monocytogenes during refrigerated storage of uncured turkey breast.
Technical Abstract: We evaluated the efficacy of potassium levulinate, potassium diacetate, and potassium propionate to inhibit Listeria monocytogenes on commercially-prepared, uncured turkey breast during refrigerated storage. Whole muscle, uncured turkey breast chubs (ca. 5 kg each) were formulated with or without potassium levulinate (0.0, 1.0, 1.5, and 2.0%), alone or in combination with potassium diacetate (0.1%) and potassium propionate (0.1%), by a commercial processor. Finished product was sliced (ca. 1.25 cm thick) and subsequently surface inoculated on both the top and bottom faces to a target level of ca. 3.5 log CFU/slice with a five-strain cocktail of L. monocytogenes. The inoculated slices were placed into nylon-polyethylene bags, vacuum-sealed, and stored at 4C for up to 90 d. The pathogen was enumerated throughout storage using the USDA package rinse/recovery method. Without inclusion of any antimicrobials in the formulation L. monocytogenes numbers increased by ca. 5.2 log CFU/slice, whereas with the inclusion of 1.0% to 2.0% of levulinate as an ingredient pathogen numbers increased by ca. 0.8 to 2.9 log CFU/slice over 90 d at 4C. In contrast, a synergistic effect was observed when levulinate was added to the batter in combination with a 0.1% diacetate and 0.1% propionate. When 1.0% levulinate and 0.1% propionate-diacetate blend were included as ingredients, pathogen numbers increased by 0.8 log CFU/slice after storage at 4°C for 90 d, whereas a decrease of ca. 0.8 log CFU/slice was observed when 1.5% or 2.0% levulinate and a 0.1% propionate-diacetate blend were included as ingredients. Our results validate that levulinate, alone or in combination with diacetate and propionate, would be effective formulation ingredients for inhibiting outgrowth of L. monocytogenes during refrigerated storage of uncured turkey breast.