Cooking history at the center point in chicken patties was quantified in terms of both time-temperature integrated indices (C and F) and endpoint temperature (Tmax). Intact cooked patties were scanned for reflectance and transmittance spectroscopy. Reflectance resulted in better calibrations for the indices of thermal history than did transmittance. Three reflectance wavelength ranges, visible (400 to 700 nm), near-infrared (1100 to 2500 nm), and visible/near-infrared (400 to 2500 nm), were evaluated, and visible/near-infrared yielded the highest accuracy. The best calibration resulted in a standard error of prediction (SEP) of 0.11 log10(min) for log10C, 0.25 log10(min) for log10F, and 2.54°C for Tmax on an independent validation sample set.