Effect of High Voltage Atmospheric Cold Plasma on Inactivation of Listeria Monocytogenes on Queso Fresco Cheese
Date
2020-12
Authors
Burrough, Lauren
Major Professor
Advisor
Mellata, Melha
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Soft cheese products are commonly implicated in listeriosis outbreaks, due to the ability of Listeria monocytogenes (LM) to grow at refrigeration temperatures and resist disinfection. Mitigation methods are available for LM; however, few avoid degradation in nutritional content and changes in flavor, color, or texture. This project aims to determine the effect of high voltage atmospheric cold plasma (HVACP) on inactivation of LM in Queso Fresco cheese. Three LM isolates from commercial cheese products were cultured in brain heart infusion broth, standardized, and spot inoculated on the surface of cheese samples. Samples were pillow packed and treated with double barrier discharge atmospheric cold plasma at 85kV for 3 minutes and incubated overnight. Treated and control samples were homogenized and serially diluted for enumeration on Brilliance™ Listeria agar. Plate counts revealed statistically significant reduction in all strains after treatment. Strains F2385, LALM-7, and LALM-8 were reduced by an average of 0.761, 0.996, and 1.15 log CFU/g, respectively. These results demonstrate the potential of HVACP in the inactivation of pathogenic LM strains isolated from commercial cheese environments. Further investigation is necessary to determine efficacy of treatment for larger sample sizes and clinical LM isolates.
Series Number
Journal Issue
Is Version Of
Versions
Series
Series
Academic or Administrative Unit
Type
Presentation