Final cooked temperature effects of ground pork on its ability to react with nitrite

Fresh ground pork patties from longissimus dorsi muscle were cooked to endpoint temperatures of 54.4 degrees C, 60.0 degrees C, 65.6 degrees C, 71.1 degrees C, 76.7 degrees C, or 82.2 degrees C. After cooking, patties were immersed in a solution of sodium nitrite (125 ppm) and water for 24 h. All patties then were heated again to a final endpoint temperature of 82.2 degrees C to allow possible formation of nitrosohemochrome. Instrumental color data, spectrophotometric 650/570 nm reflectance ratio, and visual panelists' scores on both exterior and interior surfaces revealed greater redness (pinking) at the lower initial cooked temperature endpoints. Most importantly, this study showed that all patties developed pink color on reheating, regardless of initial endpoint cooked temperature.