Alternative compounds for controlling L. monocytogenes in ready-to-eat meats.
Sodium lactate and sodium diacetate are widely used as antilisterial agents to enhance the safety of RTE products. Still, meat processors would benefit from the availability of additional antilisterial ingredients.
Controlling L. monocytogenes in ready-to-eat (RTE) meats continues to be a major concern.
The objective of scientists at Utah State University was to compare the antilisterial effectiveness of sodium levulinate (4-oxopentanoic acid), a five-carbon organic acid with GRAS status; sodium lactate; and sodium diacetate in refrigerated RTE meats. The researchers prepared turkey breast and bologna to contain: no antilisterial additives; 2% sodium lactate; sodium lactate in combination with sodium diacetate (1.75% sodium lactate, 0.25% sodium diacetate); and sodium levulinate at 1%, 2% or 3% concentrations.
The samples were sliced and inoculated with a five-strain cocktail ([10.sup.2] to [10.sup.3] CFU per [cm.sup.2]) of L. monocytogenes. Then they were vacuum-packaged and stored at 2 C for up to 12 weeks. Bacterial counts exceeded [10.sup.9] CFU per mL after six weeks in turkey and 10 weeks in bologna samples.
Sodium lactate inhibited bacterial growth for two weeks in turkey and 12 weeks in bologna. Sodium lactate with sodium diacetate inhibited growth for eight weeks in turkey and 12 weeks in bologna. In turkey breast, 1% sodium levulinate prevented bacterial growth for up to six weeks, while levels of 2% and 3% prevented growth for 12 weeks. In bologna, sodium levulinate at 1%, 2% and 3% levels completely inhibited the growth of L. monocytogenes.
Listeria-free meat samples containing various organic salts were evaluated by members of a consumer taste panel. They found that there were no differences in the acceptability of turkey breast samples or of samples of bologna.
In turkey, sodium levulinate was more effective at preventing the growth of L. monocytogenes, while in bologna it was as effective as the current antilisterial ingredients--lactate and diacetate. Adding sodium levulinate did not alter the sensory acceptability of either product.
Further information. Silvana Martini, Department of Nutrition, Dietetics and Food Sciences, Utah State University, NFS 327, 8700 Old Main Hill, Logan, UT 84322; phone: 435-797-8136; fax: 435-797-2379; email: email@example.com.