Title: Development of hyperspectral imaging technique for salmonella enteritidis and typhimurium on agar plates
Authors: Seo YW, Yoon SC, Park B, Hinton A Jr, Windham W, Lawrence K
Journal: Appl Eng Agric
Accepted date: 2014 Mar 13
Interpretive summary: Detection and enumeration of bacteria typically require the inoculation and incubation of microorganisms on agar plates before finding and picking up the presumptive positive colonies on agar plates, which is labor-intensive and time-consuming. In addition, growth of background microflora on agar plates along with foodborne pathogens such as Salmonella and Campylobacter may also significantly affect the performance of visual screening of agar plates. In this study, visible near-infrared hyperspectral imaging measuring both spatial and spectral information in the wavelength range of 400-1,000 nm was used to detect Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) on brilliant green sulfa (BGS) and xylose lysine tergitol 4 (XLT4) agar plates and differentiate them from background microflora commonly found in chicken carcass rinses. Ten classification models for Salmonella detection in the presence of background microflora were compared by testing them on the training data obtained from pure cultures of two Salmonella serotypes (SE and ST) and eight known background microflora. The accuracy in detecting Salmonella grown on BGS agar was 98%. Salmonella Typhimurium on XLT4 agar could be detected with over 99% accuracy. Validation of the Salmonella detection models on independent test samples obtained from Salmonella-spiked chicken carcass rinses inoculated on BGS agar showed the potential of hyperspectral imaging for Salmonella detection by reaching the detection accuracy rate of about 99%. The expected outcome of the research is a rapid and accurate screening tool for the detection of Salmonella colonies on agar plates.
Publication date: 2014
Related projects: Optical Detection of Food Safety and Food Defense Hazards