A chicken carcass inspection system using visible/near-infrared reflectance: In-plant trials

On-line trials of an industrial prototype visible/near-infrared spectrophotometer system developed by the Instrumentation and Sensing Laboratory for inspecting poultry for diseased and defective carcasses were conducted during an 8-day period in a slaughter plant in New Holland, Pennsylvania. Spectra (470-960 nm) of 1174 normal and 576 abnormal (diseased and/or defective) chicken carcasses were measured. The instrument measured the spectra of veterinarian-selected carcasses as they passed on a processing line at a speed of 70 birds per minute. Classification models using principal component analysis as a data pretreatment for input into neural networks were able to classify the carcasses from the spectral data with a success rate of 95%. Data from 3 days can predict the subsequent two days' chickens with high accuracy. This accuracy was consistent with the results obtained previously in off-line studies. Thus, the method shows promise for separation of diseased and defective carcasses from wholesome carcasses in a partially automated inspection system. Details of the models using various training regimens are discussed.