Antimicrobial Effects of Copper and Brass Ions on the Growth of Listeria Monocytogenes at Different Temperatures, PH and Nutrients
Listeria monocytogenes has been recognized as a human pathogen since 1929. This pathogen is found in many foods and listeriosis infections affect approximately 2,500 people in the United States each year, according to the Centers for Disease Control and Prevention. Of those infected with L. monocytogenes approximately 500 die as a result of the illness. Listeria monocytogenes is a bacterium, commonly found in water, soil, plant material, animals and human. Today, different methods are used by food manufacturers, to reduce the risk of Listeria monocytogenes, such as antimicrobial agents, heating, irradiation, and fermentation. The ability of the bacteria to grow at temperatures as low as 3°C permits multiplication in refrigerated foods. The purpose of this study was to determine the antimicrobial effect of copper ions against Listeria monocytogenes on the surface of copper, brass and concrete coated with polyurethane containing different concentrations of copper ions. The utilization of pH, nutrients and temperatures were applied. Copper alloys antimicrobial effect in two different crawfish processing plants was also evaluated. The amount of copper ions released into raw and cooked shrimp at different temperatures was also assessed. Our study has been successful in understanding the survival of Listeria monocytogenes at different copper ions concentrations under different temperatures, pH and nutrients. It has also been observed that the use of different copper ions concentrations haves great potential as antimicrobial agents that can be employed by food processors.
Advisor:Cristina Sabliov; Donal Day; Witoon Prinyawiwatkul; Jon Bell; Marlene Janes
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Date of Publication:07/13/2005