SODIUM HYPOPHOSPHITE INHIBITION OF THE GROWTH OF SELECTED GRAM-NEGATIVE FOODBORNE PATHOGENIC AND SPOILAGE BACTERIA

Sodium hypophosphite was evaluated for inhibition of growth of selected gram negative foodborne pathogenic and spoilage bacteria in laboratory media. In addition, the effects of pH and sodium chloride alone and in combination with sodium hypophosphite were examined. All inhibition studies were performed with optimal or nearly optimal growth conditions for each bacterium. Growth was monitored by measuring optical density at 600 nm, and a time to significant growth determined in each test medium. Ratios of time to significant growth in controls over that in test media were used to evaluate the effect that sodium hypophosphite and other variables had on growth. Sodium hypophosphite was most effective in inhibiting growth of gram negative facultatively anaerobic bacteria, but generally ineffective against the aerobic Pseudomonas fluorescence and microaerophilic Campylobacter jejuni strains H-840 and Smith. Results from this investigation indicate the potential use of sodium hypophosphite as an antimicrobial food preservative. Copyright © International Association ot Milk, Food and Environmental Sanitarians.