Identification and mechanism investigation of pink color defect inhibitors in cooked uncured turkey

The ability of citric acid (CA) and sodium citrate (SC) to reduce the pink color defect in irradiated and non-irradiated ground turkey and intact turkey breasts was investigated. Whey protein concentrates (WPCs) were also evaluated for their effects on the pink color defect of ground turkey and the constituents of WPC likely to reduce pink cooked color were identified. Citric acid and SC consistently reduced natural or induced pink cooked color by sodium nitrite or nicotinamide in ground turkey but had no effects on pink cooked color of intact turkey breasts. In samples cooked prior to irradiation, CA and SC reduced redness as indicated by eliminating a reflectance minimum at approximately 571nm, lessening reflectance in the red wavelength region, and preventing greater reducing conditions associated with irradiation. However, CA and SC had little effects on pink cooked color when samples were irradiated prior to cooking. In the presence of oxygen, CA and SC appear to reduce pink cooked color in ground turkey by participating in oxidative processes. Citric acid greatly reduces pH and cooking yields whereas SC does not, therefore SC represents a more viable option for reducing the pink color defect.; In ground turkey, WPCs from different companies and with different protein concentrations had varying effects on the pink color defect. Three WPCs reduced natural pinkness in cooked turkey, one WPC reduced sodium nitrite-induced pinking and two WPCs reduced nicotinamide-induced pink cooked color. Upon examination of individual constituents, calcium chloride was most effective at reducing pink cooked color. Calcium chloride required the presence of phosphate to reduce pink cooked color induced by nicotinamide and the substitution of tricalcium phosphate for sodium tripolyphosphate was an effective means to reduce the pink color defect. However, similarly to CA, tricalcium phosphate reduced pH and cooking yields. A combination of calcium chloride and SC was more effective at reducing pink cooked color induced by nicotinamide than either ingredient individually. Therefore, a combination of phosphate, calcium, and citrate represents the most viable option for poultry processors to reduce the occurrence of the pink color defect in uncured ground turkey.