VISIBLE/NIR SPECTROSCOPY FOR CHARACTERIZING FECAL CONTAMINATION OF CHICKEN CARCASSES

Zero tolerance of feces on the surfaces of meat and poultry carcasses during slaughter was established as a standard to minimize the likelihood of microbial pathogens. Microbial pathogens can be transmitted to humans by consumption of contaminated meat and poultry. Compliance with zero tolerance of feces in meat processing establishments is currently verified by visual observation. The objective of this study was to investigate the use of visible, near–infrared reflectance spectroscopy as a method to discriminate between uncontaminated poultry breast skin and feces, and to select key wavelengths for use in a hyperpspectral system. Feces (n = 102), uncontaminated poultry breast skin, and skin contaminated with fecal spots were analyzed from 400 to 950 nm. The spectra were reduced by principal component (PC) analysis. The first four PCs explained 99.8% of the spectral variation. PC 1 was primarily responsible for the separation of uncontaminated skin from feces and for the separation of uncontaminated skin from contaminated skin. A classification model was developed and evaluated to classify fecal–contaminated skin from the spectral data with a success rate of 95%. Key wavelengths were identified by intensity of loading weights at 628 nm for PC 1, 565 nm for PC 2, and 434 and 517 nm for PC 4. Discrimination was dependent on the spectral variation related to fecal color and myoglobin and/or hemoglobin content of the uncontaminated breast skin.