INACTIVATION OF FOODBORNE PATHOGENS WITH NON-THERMAL PLASMA PROCESSING AND NATURAL ANTIMICROBIALS AND GENETIC MECHANISMS UNDERLYING MICROBIAL INACTIVATION OR ADAPTATION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0218874
• Project No.: GEO01680
• Project Start Date: Aug 1, 2009
• Project End Date: Jul 31, 2014

Project Director
Critzer, F. J.

Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016

Performing Department
Center for Food Safety

Non Technical Summary
Escherichia coli O157:H7 and Salmonella spp. continue to plague the safety of our fresh fruits and vegetables, primarily because the food industry is lacking an effective means of inactivating these organisms. This project will seek to address these concerns by investigating application of plasma processing technologies, natural antimicrobials, and microbial ecology. Non-thermal plasma processing has the potential to be utilized as a means of inactivating pathogens on fresh fruits and vegetables while maintaining product quality; however, this technology is in its infancy and much research is still required to validate it prior to its application by the food industry. Natural antimicrobials will also be studied to determine their stability and efficacy in a produce rinse solution. These antimicrobials are gaining wider use by the food industry as consumers begin to demand more natural ingredients and food processing aids. We will seek to determine what processes affect their stability, and how their activity against foodborne pathogens can be improved. Gene expression profiles can give insights to microbial ecology and help researchers determine the best timing and application of interventions to help improve the overall safety of a food product. Through these studies, we will be able to determine how microorganisms adapt to interventions, like chlorine washes, and the best timing of interventions, such as when the cells are in distress, to improve the overall reduction of pathogens. This research will add to the scientific knowledge that is necessary to help improve the safety of fresh fruits and vegetables.

Animal Health Component

(N/A)

Research Effort Categories

Basic

25%

Applied

75%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
712	4010	1100	75%
712	4010	1080	25%

Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
4010 - Bacteria;

Field Of Science
1080 - Genetics; 1100 - Bacteriology;

Keywords

foodborne pathogens

escherichia coli o157:h7

salmonella

non-thermal plasma processing

natural antimicrobials

sanitizers

fruits and vegetables

microbial ecology

gene expression

efflux pumps

Goals / Objectives
The goal of this project is to investigate new intervention strategies for inactivation of foodborne pathogens. We will also seek to determine the microbial ecology of foodborne pathogens when common intervention strategies are applied. Fresh or minimally processed fruits and vegetables continue to be a source of foodborne pathogens. This research will investigate non-thermal means of inactivating these pathogens to improve the overall safety of these commodities. Insights to genetic adaptation and survival to commonly used intervention strategies in fruit and vegetable processing will help determine the best means by which to apply hurdle technologies in order to inactivate pathogens.

Project Methods
Intervention strategies will be evaluated amongst E. coli O157:H7 and Salmonella enterica serovars both in vivo and vitro to determine their application in the food industry. Reduction, inhibition, or growth will be compared to non-treated controls to determine the efficacy of these interventions. Gene expression profiles will be conducted by harvesting messenger RNA from control and treated pathogens and comparing the mRNA levels to give insights to mechanisms of adaptation or bacterial stress.

Progress 08/01/09 to 07/31/14

Outputs
OUTPUTS: pi has terminated therefore, we are terminating this project PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
nothing to report pi has terminated

Publications

• nothing to report pi has terminated 2011

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Eugenol, carvacrol and cinnamic aldehyde are being investigated to determine the impact of oxidation on the efficacy of these naturally occurring antimicrobial phenolic compounds. It is important to determine the impact of oxidation on the antimicrobial activity of these compounds if they are to be utilized in food systems or as an intervention step such as a produce rinse. The findings of this research will be presented at the Annual Meeting of the International Association for Food Protection, the premier professional organization focused on food safety. PARTICIPANTS: Grishma Kotwal, a Master's Candidate in the Department of Food Science and Technology, conducted the research associated with Objective 2a. This provided training and professional development for Ms. Kotwal's Thesis project. Ms. Kotwal plans to begin work in the food industry once she has completed her graduate degree. TARGET AUDIENCES: Food industry, focusing on application in new product development. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The antimicrobial activity of these compounds is slightly reduced when exposed to conditions that drive oxidation, such as heat. Therefore, manufacturers must increase the concentration of these compounds if they wish to inhibit the growth of E. coli O157:H7 or Salmonella in their products.

Publications

• No publications reported this period