Inactivation of Listeria monocytogenes on Beef Bologna and Cheddar Cheese Using Polyvinyl‐idene Chloride Films Containing Sorbic Acid

Abstract

ABSTRACT: Polyvinylidene chloride (PVDC, SaranR F‐310) films containing sorbic acid (0%, 1.5%, and 3.0% w/v) were prepared with use of a solvent‐casting method and were then placed between slices of commercially produced beef bologna that were previously surface‐inoculated with L. monocytogenes at 103 or 105 CFU/g. In addition, cubes of commercial Cheddar cheese were surface‐inoculated to contain 103 or 105Listeria monocytogenes colony‐forming units (CFU) /g and then wrapped with the sorbic acid‐containing films. Films containing 1.5% and 3.0% (w/ v) sorbic acid prevented growth of L. monocytogenes on bologna slices with populations as much as 7.1 logs lower after 28 d of storage at 4 °C compared with the sorbic acid‐free controls. In contrast, numbers of Listeria remained relatively stable on Cheddar cheese with populations decreasing < 1.3 logs after 35 d of storage. With use of the sorbic acid‐containing films, common spoilage organisms were also inhibited on both products. After 28 d of contact with bologna and Cheddar cheese, these films retained 7% and 60% of their original sorbic acid content, respectively, with the control film retaining 85% of its original sorbic acid content. Given these findings, sorbic acid‐containing films may be useful in enhancing the safety and shelf‐life of ready‐to‐eat delicatessen products.