Optical Detection of Microbial Contamination in Food Matrices

The goal of this proposed research is the development of a rapid optical method for the detection of food borne pathogens in food matrices. A host of optical detections methods including hyperspectral imaging, Raman spectroscopy, and infrared microscopy have been refined and offer opportunities including the potential for real-time detection for identification and quantification of microorganisms in food matrices. This project proposes to investigate these techniques for their ability to detect and validate the presence of food borne pathogens in food matrices. The two research groups (University of Kentucky (UK), Lexington, KYand the Quality & Safety AssessmentResearchUnit, USDA ARS, Athens, GA) will collaborate on this research. ARSwill collect background optical information on pure cultures of pathogens in plates and solutions and this information will be used to determine the identifiable detection levels of pathogens in food matrices. UK will develop a microbial separation technique to separate microorganisms from the food solids in matrices to enhance the opportunity for optical identification and an ultrasonic technique will be tested for concentrating microorganisms in solutions. An ultrasonic standing wave system and hyperspectral imaging system will be combined to enhance the limits of detection of microorganisms in solution. The second phase of this project will utilize the information collected to develop and test the most promising techniques. ARSwill use the most promising techniques including food rinse for identification of organisms in matrices. The University of Kentucky group will utilize a combination of hyperspectral imaging and ultrasonic concentration techniques to determine a lower concentration threshold for detection. This research will cumulate with a proposed system for rapid optical identification of pathogens, a gap analysis and performance enhancement for improving detection accuracy and reducing detection time of the identified methods, and an evaluation the commercial potential and limitations of potential rapid screening systems developed.