Inhibition of Listeria monocytogenes and Escherichia coli O157:H7 on Beef by Application of Organic Acids

Abstract

Lean beef surfaces were inoculated with Escherichia coli O157:H7 and Listeria monocytogenes and then sanitized with fumaric, acetic, or lactic acid alone and in combined solutions of those acids at 55°C for 5 s. The initial inoculum level was 8.62 log CFU/cm2 and 5.13 log CFU/cm2 for L. monocytogenes and E. coli O157:H7, respectively. Fumaric acid at a concentration of 1% was the most effective acid in reducing the populations of L. monocytogenes by up to 1 log unit and E. coli O157:H7 by up to 1.3 log units when compared with acetic or lactic acids. The rank order of acids tested against the growth of L. monocytogenes and E. coli O157:H7 was fumaric acid followed by lactic and acetic acids. Fumaric acid at concentrations of 1.0% and 1.5% was more effective than any of the combined solutions of acids.

Sodium butyrate improves growth performance of weaned piglets during the first period after weaning

“…As a consequence, there is an increasing need to find generally recognized as safe (GRAS) alternatives to modulate cecal microflora and control intestinal fermentation. Among these substances are some organic acids which are known to be very effective inhibitors of microbial growth and are therefore intentionally added to many foods as preservatives (Knochel and Gould, 1995;Podolak et al, 1996). Adding organic acids such as citric, formic, fumaric, lactic or propionic acid to piglet diets has been reported to be helpful in overcoming problems of the post-weaning period (Falkowski and Aherne, 1984;Partanen and Mroz, 1999).…”

Lactic Acid Permeabilizes Gram-Negative Bacteria by Disrupting the Outer Membrane

“…As reviewed by Doores (8), lactic acid is able to inhibit the growth of many types of food spoilage bacteria, including gram-negative species of the families Enterobacteriaceae and Pseudomonadaceae. Among other organic acids, lactic acid is recognized as a biopreservative in naturally fermented products (25), and numerous applications for decontamination of meat by lactic acid have been described (7,10,22,29,32,33). The antibacterial action of lactic acid is largely, but not totally, assigned to its ability in the undissociated form to penetrate the cytoplasmic membrane, resulting in reduced intracellular pH and disruption of the transmembrane proton motive force (25).…”

Reexamining intra and extracellular metabolites produced by Pseudomonas aeruginosa

“…Subsequently four selected strains were able to produce antimicrobial compounds as well as agents causing zinc solubilization and Podolak et al [30] suggested that the antimicrobial effect can be due to organic acids that cause a reduction in pH, so it can be assumed that the organic acids that are acting as antimicrobial agents on one side can act as agents causing zinc solubilization on another because as mentioned above acid production is an important phenomenon in metal solubilization.…”