Abstract
Color and fluorescence spectrometry were evaluated as rapid, objective tools for verifying the cleanliness of poultry-processing food-contacting surfaces contaminated with a model chicken solution across six common materials. Both techniques detected chicken residues at dilutions several orders of magnitude below human visual and olfactory thresholds, with stainless steel and blue plastic yielding the largest color differences between clean and contaminated states and fluorescence measurements remaining highly sensitive on all tested surfaces. Representative limits of detection were on the order of 1:50-1:100 dilution of chicken residue for color measurements on most surfaces and approximately 1:50 for fluorescence measurements, compared with human detection thresholds of approximately 1:50. Cleaning chemicals routinely used in poultry plants did not measurably reduce detection performance, and a simple machine learning classifier further improved separation of clean versus contaminated readings. These findings indicate that compact color and fluorescence instruments can provide fast, quantitative pre-sanitation checks that strengthen SSOP verification and reduce reliance on subjective human inspection in poultry processing facilities.