Purpose: Our objectives were to demonstrate the efficacy of chlorine dioxide (ClO2) gas for inactivation of Salmonella on green tomatoes and its effect on maturation quality, and to develop analysis for this process.
Methods: Mature green tomatoes were dip inoculated with Salmonella Montevideo and were stored at 13°C for 24h prior to processing. Gaseous ClO2 treatments of inoculated tomatoes were conducted at 0.2, 0.4, and 0.8 mg/l air for 2, 4, and 8h. Treated and non-treated tomatoes were then stored in modified atmosphere (97% Nitrogen, 3% Oxygen) at 13°C and 90% relative humidity for 5 days, and then were stored for an additional 7 days in a standard atmosphere at 21°C and 75% relative humidity to allow for ripening.
Results: Gaseous ClO2 treatments significantly reduced Salmonella populations in excess of 3.0 log CFU/g tomato. Color and texture profiles of ripened treated tomatoes were not significantly different from the ripened control samples. The cost estimates under the laboratory conditions used indicated that this treatment might add $0.17 per kg tomato.
Significance: These results indicate that ClO2 gas phase treatments could enhance the microbiological safety of tomatoes and extended the shelf life without affecting the ripening process. Although, an increase of $0.17 in cost per kg might be considered to be prohibitive at this point, the decrease in economic losses due to extending the shelf life, and the adoption of this technology under commercial production conditions would reduce these associated costs.