Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2011
Publication Date: 9/1/2011
Citation: Perez Diaz, I.M. 2011. Preservation of acidified cucumbers with a combination of fumaric acid and cinnamaldehyde that target lactic acid bacteria and yeasts. Journal of Food Science. 76(7):M473-M477.
Interpretive Summary: This manuscript describes the potential application of fumaric acid to prevent growth of lactic acid bacteria in preserved cucumber tanks. Fumaric acid is not effective at controlling growth of spoilage yeasts, thus an additional agent must be identified to achieve microbial stabilization of the product.
Technical Abstract: The naturally occurring compound, fumaric acid, was evaluated as a potential preservative for the long-term storage of cucumbers. Fumaric acid inhibited growth of lactic acid bacteria (LAB) in an acidified cucumber juice medium model system resembling conditions that could allow preservation of cucumbers in the presence of sodium benzoate. Forty millimolars of fumaric acid were required to inhibit growth of an extremely aciduric Lactobacillus plantarum LA0445 strain at pH 3.8. Half of this concentration was required to achieve inhibition of L. plantarum LA0445 at pH 3.5. As expected growth of the spoilage yeasts Zygosaccharomyces globiformis and Z. bailii was not inhibited by fumaric acid at near saturation concentrations in the same cucumber juice medium. To usefully apply fumaric acid as a preservative in acidified foods it will be necessary to combine it with a food grade yeast inhibitor. The antimicrobial agent, cinnamaldehyde (3.8 mM) prevented growth of Z. globiformis as well as the yeasts that were present on fresh cucumbers. Acidified cucumbers were successfully preserved, as indicated by lack of yeasts or LAB growth and microbial lactic acid or ethanol production by a combination of fumaric acid and cinnamaldehyde during storage at 30 °C for 2 mo. This combination of 2 naturally occurring preservative compounds may serve as an alternative approach to the use of sodium benzoate, potassium sorbate, or sodium metabisulfite for preservation of acidified vegetables without a thermal process.