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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #359151

Research Project: Ecology and Detection of Human Pathogens in the Produce Production Continuum

Location: Produce Safety and Microbiology Research

Title: Gaseous antimicrobial treatments to control foodborne pathogens on almond kernels and whole black peppercorns

item RANE, BHARGAVI - University Of Maine
item Bridges, David
item Wu, Vivian

Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2020
Publication Date: 6/26/2020
Citation: Rane, B., Bridges, D.F., Wu, V.C. 2020. Gaseous antimicrobial treatments to control foodborne pathogens on almond kernels and whole black peppercorns. Food Microbiology. Volume 92.

Interpretive Summary: The significance of this research was to obtain an in-depth analysis of gaseous antimicrobials ClO2 and O3 on low moisture foods (almonds and whole black peppercorn). These antimicrobials were chosen due to their strong oxidizing capabilities and have proven to be efficient in disinfection of fresh food models in our previous studies. Post-treatment results showed that ClO2 achieved significant bacterial reductions on almonds and peppercorn when combined with heat or relative humidity. The conclusion obtained from this research is expected to expand the application of gaseous ClO2, an environmental-friendly food safety solution, as a hurdle treatment on almonds and black peppercorn.

Technical Abstract: Treatment with gaseous antimicrobials, such as chlorine dioxide (ClO2) and ozone (O3), have been considered for the control of foodborne pathogens (e.g. Shiga-toxin producing Escherichia coli, Salmonella and Listeria monocytogenes) to ensure food safety without affecting the food quality. Almonds were treated at 0.27 and 0.40 mg ClO2/g almond for 4 h and 6 h, respectively. Peppercorns were treated with 0.29 mg of ClO2/g and 0.40 mg of ClO2/g of sample for 2.5 h and 4 h, respectively. The concentration of gaseous O3 (corona discharge method) used was 17.83 µg O3/g for almonds for 6hr, and 2hr and 4hr for peppercorn. Treatment for almonds was hurdled with post-treatment heat at 50oC and 65oC for both gases. Increase in relative humidity was studied at 45% and 80% for ClO2 treatment on peppercorn. Gaseous ClO2 combined with heat provided bacterial reductions between 2.9 – 4.6 log for all pathogens tested on almonds at variable conditions, while ClO2 in combination with RH obtained up to 2.5 – 3.7 log reductions for all pathogens on peppercorn. No visual damage was observed on the foods. In conclusion, treatments with ClO2 was more effective than treatments with O3.