Date of Award

12-2015

Degree Type

Thesis

Degree Name

Master of Science

Major

Food Science and Technology

Major Professor

P. Michael Davidson

Committee Members

Qixin Zhong, Faith Critzer

Abstract

There is a need for the development of a “natural” sanitizing agent to reduce or eliminate foodborne pathogens that meets USDA organic standards, as an alternative to chlorine. The sanitizer needs to eliminate foodborne pathogens and prevent cross contamination in rinse liquids in the presence of organic matter. In this study, the focus was to evaluate a natural antimicrobial-based sanitizing (NABS) agent in rinse liquids to determine if it was capable of eliminating foodborne pathogens on organic produce through cross-contamination studies. Five-serovar/strain cocktails of pathogenic bacteria were combined to form an inoculum cocktail, which was used to inoculate the produce. The produce was introduced into the NABS treatments (with or without organic load) or 200 ppm NaOCl and enumerated for initial reduction. To determine if cross-contamination occurred in the rinse liquids, un-inoculated produce was introduced into the shared rinse liquid container. The greatest initial reductions occurred when tomatoes inoculated with E. coli were introduced into the NaOCl rinse liquid (> 3.0 log CFU/g) and when the spinach samples were introduced into the 0.75% NABS (1.3 log CFU/g). Overall, cross-contamination was prevented, when compared to the water controls. Enumerating for potential survivors of pathogenic bacteria in the rinse liquids validated the prevention of cross-contamination. The addition of the organic load to the rinse liquids did not affect the efficacy of NABS, except for the case of the cantaloupes. In conclusion, NABS did not demonstrate practical initial reductions on the inoculated produce when compared to the controls, however, NABS was able to prevent cross-contamination in the rinse liquid.

Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS