ARS | Publication request: LETHAL AND SUBLETHAL ACTION OF ACETIC ACID ON SALMONELLA IN VITRO AND ON CUT SURFACES OF APPLE SLICES

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 22, 2003
Publication Date: December 22, 2003
Citation: LIAO, C., SHOLLENBERGER, L.M., PHILLIPS, J.G. LETHAL AND SUBLETHAL ACTION OF ACETIC ACID ON SALMONELLA IN VITRO AND ON CUT SURFACES OF APPLE SLICES. JOURNAL OF FOOD SCIENCE. 2003. V. 68(9). P. 2793-2798.

Interpretive Summary: Five out of 15 outbreaks of human illness have been associated with consumption of apple or orange juices contaminated with Salmonella. Effective methods for removing the pathogen from fruits are needed to ensure the safety of fresh and fresh juice products. Accordingly, we investigated the antimicrobial effects of acetic acid (AA, an active ingredient of vinegar) on Salmonella and evaluated the potential of AA as a sanitizer for fresh produce. It was found that the antimicrobial action of AA on Salmonella was dependent on acid concentration, exposure time, culture age, and bacterial strain tested. We also compare the efficacies of five sanitizer treatments for eliminating Salmonella from apple slices and found that washing apple slices with a combination of AA and another sanitizer (hydrogen peroxide) was able to remove 99.99 percent of Salmonella on apple slices. The potential of using AA in combination with other disinfectants appears to be a viable and effective method for assuring the microbial safety of fresh produce.

Technical Abstract: Acetic acid (AA) has been approved by the U. S. Food and Drug Administration for use as an additive for food preservation and as a disinfectant for cleaning animal carcasses. The objective of this study was to investigate the potential of using AA for decontamination of fresh produce. Lethal and sublethal action of AA on Salmonella as affected by acid concentration, exposure time, culture age and bacterial strain were investigated. Relative susceptibility of six Salmonella strains to AA antimicrobial action was in a decreasing order of: S. bareilly, S. typhimurium, S. montevideo, S. poona, S. mbandaka, S. stanley. Stationary-phase cells of S. mbandaka were 100-fold more resistant to AA action than log-phase cells. Washing apple disks with sodium hypochlorite, hydrogen peroxide, AA, or tridosium phosphate reduced the number of Salmonella by 10- to 100-fold and 30-40 percent of cells that survived the treatments were injured. The most effective among the five sanitizer treatments tested was a mixture of 5 percent AA and 5 percent hydrogen peroxide, which reduced the population of Salmonella on apple disks by as high as 4 log units.