Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2014
Publication Date: 7/14/2014
Citation: Sun, X., Bai, J., Ference, C.M., Wang, Z., Narciso, J.A., Zhou, K. 2014. Antimicrobial activity of controlled-release chlorine dioxide gas on fresh blueberries. Journal of Food Protection. 77:1127-1132. Interpretive Summary: Chlorine dioxide can be used as a sanitizer for controlling foodborne pathogens as well as yeasts and molds on blueberries. The findings in this study suggest that chlorine dioxide treatment in active packaging is useful in improving the microbial safety of blueberries and reducing decay during storage without impairing the fruit quality.
Technical Abstract: The effect of chlorine dioxide (ClO2) on the safety and quality of blueberries was studied. In vitro studies revealed that both ClO2 gas fumigation and ClO2 water direct contact killed food pathogen bacterium, Escherichia coli and fruit decay pathogen fungus, Colletotrichum acutatum. In vivo studies were conducted using non-inoculated berries and berries inoculated with postharvest decay and food pathogens. Berries were inoculated with either E. coli (5.2 log CFU/g) or C. acutatum (3.9 log CFU/g). Inoculated fruit were dried for 2 h at room temperature, and packed in perforated commercial clamshells, with or without ClO2 pad, and stored at 10°C for up to 9 days. The effect of ClO2 on microbial populations and fruit firmness was monitored during storage. In the inoculation experiment, treatment with ClO2 reduced population of E. coli and C. acutatum by 2.2 to 3.3, and 1.3 to 2.0 log CFU/g, respectively. For the non-inoculated blueberries, initial total aerobic bacteria count (TBC) and yeasts/molds count (YMC) was 4.2 and 4.1 log CFU/g, respectively. ClO2 treatment reduced TBC and YMC by 1.5 to 1.8, and 1.3 to 1.7 log CFU/g, respectively. The firmness of both inoculated and non-inoculated blueberries was maintained by ClO2 treatment. Thus, time-release ClO2 gas technology shows promise as an effective and practical antimicrobial agent in commercial clamshell packaging in blueberry and other fruits.