2010 Annual Report
1a.Objectives (from AD-416)
Develop, test, and prototype rapid optical systems and methods to detect food contaminants, particularly contaminants found in the poultry industry such as fecal contaminants on poultry carcasses. Develop optical systems to detect intentional and unintentional biological, physical, and chemical contamination of food products.
1b.Approach (from AD-416)
A real-time on-line fecal detection system, which consists of a multispectral imaging camera, lighting, and detection algorithm, will be prototyped. Multispectral and hyperspectral imaging systems will be used to identify physical hazards in poultry meat. Hyperspectral imaging in transmission mode will be used with structured lighting to identify embedded bones in breast filets. Hyperspectral imaging will also be used with white and brown shell eggs to identify both internal defects such as blood spots, meat spots, and bacterial contamination, and external defects such as fecal matter on shells and cracked shells. Hyperspectral imaging systems will be also be used to identify bacterial and chemical agents in meat and meat products. Collaboration with ARS Instrumentation and Sensing Laboratory, BARC, FSIS, and the University of Georgia Biological and Agricultural Engineering Department will be used to aid and enhance the research.
Prototype Line-Scan Real-time Hyperspectral Imaging System. The ARS three-band multispectral imaging system was able to detect fecal contaminants in real-time during poultry processing. ARS and their industry partner are now merging the fecal detection and systemic disease detection systems onto a common platform with a line-scan hyperspectral imaging system and in-house application software written in C++ which is suitable for other applications and can support several cameras and different image processing functions. The prototype line-scan hyperspectral imaging system has demonstrated feasibility in terms of processing speed and detection accuracy for real-time, on-line fecal detection. This system will aid commercialization by creating one system with user-defined wavelengths that can be installed at different locations of the processing line to solve different food safety problems.
Rapid Methods for Campylobacter Detection on Agar Plates. A hyperspectral imaging technique was developed to discriminate Campylobacter colonies on agar plates from non-pathogenic microorganisms. A real-time imaging system with a digital camera and optical filter has been developed to demonstrate feasibility. The imaging software can highlight and automatically count colonies. The developed protocol for Campylobacter colonies was also explored as a method for discriminating non-O517 Shiga toxin-producing E-coli colonies.
Shiga Toxin-Producing Escherichia coli (STEC) Detection on Agar Plates. Highly human-virulent E. coli O157:H7 STEC strains can cause bloody diarrhea and potentially fatal complication called hemolytic uremic syndrome. Recently an increasing number of strains have been isolated but are time-consuming and not effective for presumptive screening of large amount of food samples. An imaging method, known as hyperspectral imaging, is being developed to discriminate six common non-O157 serotypes. Preliminary tests with three different agar types showed potential for rapid screening of food samples with STEC organisms on rainbow agar plates.
Food Toxin Detection with DNA Aptamers. Several experimental protocols were developed to detect ricin with specific DNA aptamers and an atomic force microscope-based fast single-molecule recognition system. Ultimately, this label-less sensing technique will enhance detection accuracy with high speed methods to detect multiple agents with advanced DNA aptamer nanochips which will benefit to the U.S. consumer of food products as well as protect people from biothreat risk.
Detection of Huanglongbing Infected Citrus Plants. The U.S. citrus industry needs a method to detect Huanglongbing disease (HLB) and rapidly screen commercial orchards at minimal cost. Our previously developed near-infrared reflectance spectroscopy method was able to accurately discriminate between HLB infected leaves and non-infected leaves. The calibration database has been expanded to include leaves with other citrus diseases and deficiencies of plant-essential nutrients. The database has been transferred to the ARS Horticultural Research Laboratory and is being tested on commercial orchard leaf samples.
Rapid Methods for Campylobacter Detection on Agar Plate. In the poultry industry, contamination of poultry meat with foodborne pathogens (especially, Salmonella and Campylobacter) is an important food safety concern. Although techniques such as enzyme immunoassays and polymerase chain reaction are commercially available for rapid detection and identification of pathogens, time-consuming culture-based methods are still the most reliable and accurate “gold standard” techniques and are widely adopted by the industry and regulatory agency laboratories for presumptive positive pathogen detection from high-volume samples. In addition to the lengthy processing time, another challenge to the culture-based methods is unwanted background microflora that also grows with and looks similar to the target microorganisms. ARS researchers in Athens, GA have developed a non-destructive advanced imaging technique using hyperspectral imaging for the automated presumptive screening and enumeration of pure Campylobacter-pathogen colonies on agar plates. The researchers also built a prototype real-time imaging system with a single-band optical filter and a monochrome digital camera for demonstrating the feasibility of a cost-effective multispectral imaging system. The developed hyperspectral imaging technique will be confirmed with mixed-cultures obtained from real-food samples.
Hawkins, S.A., Park, B., Poole, G.H., Gottwald, T.R., Windham, W.R., Lawrence, K.C. 2010. Detection of Citrus Huanglongbing by Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR) Spectroscopy. Applied Spectroscopy. 64:100-103.
Yoon, S.C., Lawrence, K.C., Line, J.E., Siragusa, G.R., Feldner, P.W., Park, B., Windham, W.R. 2010. Detection of Campylobacter Colonies using Hyperspectral Imaging. Sensing and Instrumentation for Food Quality and Safety. Vol. 4, Issue 1. pg. 35-49.
Kise, M., Park, B., Heitschmidt, G.W., Lawrence, K.C., Windham, W.R. 2010. Multispectral imaging system with interchangeable filter design. Computers and Electronics in Agriculture. 72(2):61-68.
Hawkins, S.A., Park, B., Poole, G.H., Gottwald, T.R., Windham, W.R., Albano, J.P., Lawrence, K.C. 2010. Comparison of FTIR spectra between huanglongbing (citrus greening) and other citrus maladies. Journal of Agricultural and Food Chemistry. 58(10):6007-6010.
Windham, W.R., Kandala, C.V.K., Sundaram, J., Nuti, R.C. 2010. Determination of peanut pod maturity by near-infrared reflectance spectroscopy. Transactions of the ASABE. 53(2) 491-495.