Gaseous chlorine dioxide maintained the sensory and nutritional zuality of grape tomatoes and reduced populations of salmonella enterica serovar typhimurium

Authors: WANG, LIN - Non ARS Employee; Sokorai, Kimberly; Wu, Vivian; Fan, Xuetong

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2018
Publication Date: 9/21/2018
Citation: Wang, L., Sokorai, K.J., Wu, V.C., Fan, X. 2018. Gaseous chlorine dioxide maintained the sensory and nutritional zuality of grape tomatoes and reduced populations of salmonella enterica serovar typhimurium. Food Control. 96:299-309. https://doi.org/10.1016/j.foodcont.2018.09.023.
DOI: https://doi.org/10.1016/j.foodcont.2018.09.023

Interpretive Summary: There have been a number of reports on the effectiveness of gaseous chlorine dioxide in inactivating various human pathogens associated with fresh produce. However, studies dealing with both microbial reduction and impact on quality and nutrients of tomatoes are scarce (if any). The present study determined the efficacy of gaseous chlorine dioxide in inactivating Salmonella, and the impact on sensory and nutritional quality of grape tomatoes. Results demonstrated that gaseous chlorine dioxide reduced populations of Salmonella by 99.99% on tomatoes. Appearance, texture, color, odor, and lycopene and ascorbic acid contents of tomatoes were not significantly affected by the treatment during 21 days of storage at 10 C. Therefore, gaseous chlorine dioxide can be used to enhance microbial safety of grape tomatoes without compromise in sensory and nutrient quality of the fruit.

Technical Abstract: There have been numerous reports on the effectiveness of gaseous chlorine dioxide (gClO2) in inactivating various human pathogens associated with fresh produce. However, studies dealing with both microbial reduction and impact on quality and nutrients of tomatoes are scarce. In the present study, gaseous chlorine dioxide (gClO2) was evaluated for its effectiveness on populations of Salmonella and native microorganisms on grape tomatoes, and on sensory and nutritional quality. Grape tomatoes, dip inoculated with a cocktail of Salmonella enterica serovar Typhimurium, were treated with three different levels of gClO2 generated by sachets containing sodium chlorite and reducing acids for up to 5 h in 20-L chambers. For the quality study, non-inoculated fruits were treated similarly with the gClO2, and stored for 21 d at 10 °C. Sensory and nutritional quality, aerobic plate count, and yeast and mold count were measured at 1, 7, 14 and 21 d of storage. Headspace gClO2 concentrations and humidity in the chambers were measured during the treatments. Concentrations of gClO2 in the chamber were relatively stable during the 2.5 and 5 h treatment times. Gaseous ClO2 at 1.9 mg/L for 5 h and 4.3 mg/L for 2.5 and 5 h reduced Salmonella populations from 5.4 log CFU/fruit to a non-detectable level (detection limit 1.70 log CFU/fruit). However, populations of native microflora were not consistently affected by the gClO2 treatments. Furthermore, the treatments did not have any significant effect on appearance, off-odor, firmness, color, or lycopene and vitamin C contents of grape tomatoes during the 21-d storage. Overall, gClO2 treatments that achieved more than 4 log reductions of Salmonella did not significantly (P>0.05) affect sensory or nutritional quality of grape tomatoes.