ANTIBACTERIAL ACTIVITY OF SEVERAL ORGANIC-ACIDS COMMONLY USED AS FOOD-ADDITIVES

Among 9 organic acids commonly used as food additives in Japan, fumaric acid (FA) exhibited the strongest growth-inhibiting (GI) action on 20 Gram-negative bacterial strains tested. Growth of these 20 strains, including 3 Salmonella serovars, Escherichia coli, E. cloacae, Klebsiella oxytoca, K. pneumoniae, Acinetobacter anitratus, Proteus mirabilis, or Pseudomonas aeruginosa, was inhibited within 160 seconds of contact with 0.3 w/v% solution of FA, although strains of S. Typhimurium exhibited lower susceptibility than the others. Both Bacillus cereus and Staphylococcus aureus were resistant to the GI action of FA and other organic acids. The GI action of FA was remarkably improved by the addition of 0.3 similar to 0.1% ascorbic acid, malic acid, tartaric acid or citric acid monohydrate.