ENHANCED INHIBITION OF LISTERIA-MONOCYTOGENES BY GLYCEROL MONOLAURATE WITH ORGANIC-ACIDS

Glycerol monolaurate (ML) inhibition of Listeria monocytogenes was affected by pH and testing matrix. We investigated antimicrobial effects of ML combined with acetic, benzoic, citric, and lactic acids (AA, BA, CA, and LA) on L. monocytogenes in broth medium and crawfish tail meat. Minimum inhibitory concentrations were lower when ML was combined with each acid in dual combination. ML combined with sublethal amounts of AA, BA, or LA gave greater inhibition than for the most active compound alone. No interaction occurred between ML and CA. ML had no influence on pH of media containing organic acids. ML or LA in crawfish tail meat had reduced activity. ML activity was influenced by type of organic acid used. Combining ML with organic acids may provide similar protection to other precooked ready-to-eat foods.