Development of Handheld Two-Band Spectral Imaging System for Food Safety Inspection

Spectral sensing has been widely utilized for detecting foodborne contaminants. The objective of this research was to develop a handheld multispectral instrument for food safety inspection for poultry and other foodstuffs. The prototype system developed in this research consisted of a compact two-band spectral imaging system, LED light, and handheld computer. The two-band spectral imaging system was a two-port imaging system that consisted of two identical digital monochrome cameras, optical system, and two narrow bandpass filters. By incorporating an interchangeable filter design, the imaging system can measure any two spectral bands in the 400 to 1000 nm portion of the spectrum without any complicated manufacturing process. That is a great advantage in terms of the selection of the spectral bands, as compared to conventional multispectral imaging systems that integrate filters and sensors in one unit. Lens distortions and geometric misalignment of the two cameras were mathematically corrected, resulting in co-registered two-band images. The prototype system was tested with poultry carcasses, and the preliminary results showed that the handheld two-band spectral imaging system could effectively detect feces and ingesta on the surface of poultry carcass.