Inhibition of Pantoea agglomerans contamination of fresh-cut jackfruit by exposure to weak organic acid vapors

Abstract

Fresh-cut jackfruit, purchased from markets in urban areas of Bangkok, were examined for bacterial contamination. Pantoea agglomerans was the predominant contaminant bacterium occurring in 90% of the 30 samples tested; many with high loads. Inhibition of surface contamination of P. agglomerans by vinegar, lactic acid or citric acid, either as liquid or vapor, were tested in vitro. For liquid-phase exposure, vinegar had a higher inhibitory effect than the other two, both of which that gave only slight inhibition. Exposure to vinegar vapor containing 3.36 mmol L−1 acetic acid for 90 min gave complete inhibition of P. agglomerans. In order to test this vaporized vinegar treatment on the quality of jackfruit, non-inoculated samples, with or without vinegar treatment, were stored for 7 d at 5 ± 2 °C and then tested by a sensory evaluation panel. Results showed that in all the attributes tested, color, texture and overall acceptability, vaporized vinegar treated sample were preferred to non-treated samples. It was concluded that exposure of fresh-cut jackfruit to vaporized vinegar is a simple method of controlling surface bacterial contamination without detrimentally affecting their acceptability.