Purpose: The purpose of this investigation was to study kinetics of inoculated Salmonella Typhimurium on tangerine and green pepper by aerosolized CD treatment and to determine the effect of aerosolized CD on the quality and residual concentrations on the produce.
Methods: The tangerine and green pepper inoculated with Salmonella Typhimurium were treated to various concentrations of CD which was aerosolized by use of jet and ultrasonic nebulizer for different treatment times. The antimicrobial activity of the aerosolized CD prepared by jet nebulizer and ultrasonic nebulizer were compared.
Results: In the CD generation efficiency, the phosphoric acid as an acidulant to react with sodium chlorite produced relatively higher concentration of CD than the other acids and the purity of CD was 96~98%. Bacterial numbers reduced as increase of aqueous chlorine dioxide concentration and treatment time. In the treatment of aerosolized CD prepared by jet nebulizer, the bacterial reductions on tangerine and green pepper were 2.98, 3.12 log for 60 min at 300 ppm of CD, 3.81, 4.21 log for 60 min at 400 ppm and D-values were 16.47 and 14.84 min, respectively. However, aerosol CD by ultrasonic nebulizer treatment for 60 min at 300 and 400 ppm on tangerine and green pepper surface showed undetectable levels of S. Typhimurium and D-values were 5.04 and 4.92 min, respectively. Residual concentrations of tangerine and green pepper were less than 1.5 ppm. Aerosolized CD treatment caused negligible changes in Hunter color L, a, and b values and did not affect the color of tangerine and green pepper during storage.
Significance: These results indicate that aerosolized CD treatment can be useful in improving the microbial safety and quality of fresh produce.