Inhibition of pinking in cooked, uncured turkey rolls through the binding of non-pinking ligands to muscle pigments

The pink color defect in cooked, uncured turkey is a sporadic problem which can result in consumer dissatisfaction. Nicotinamide hemochrome may be one of the major pigments responsible for this defect. Reflectance (400-700 nm) methodology was developed to reliably and easily quantify (%R 537 nm/%R 553 nm; r = 0.993) the presence of nicotinamide hemochrome.

Fourteen ligands were tested in a ground turkey system to determine their ability to reduce pinking in control samples and in the presence of pinking agents (1.0% nicotinamide or 150 ppm sodium nitrite). Trans 1,2-diaminocyclohexane-N,N,N’,N’ tetraacetic acid monohydrate (CDTA); diethylenetriamine pentaacetic acid (DTPA), ethylenedinitrilo-tetraacetic acid disodium salt (EDTA), and calcium reduced non-fat dry milk (NFDM) were the most effective at reducing pinking with and without pinking agents.

These four ligands were evaluated in intact turkey breasts with and without added pinking agents (1.0% nicotinamide or 20 ppm, 100 ppm sodium nitrite). Ligands were evaluated at various levels (50, 100, 200 ppm; except NFDM 1.0% or 2.0%), over three storage times (1, 14, 21 days), and after two minutes of exposure to light and air. When ligands were evaluated without pinking agents, samples were generally lighter and less pink than controls. In the presence of added pinking agents, the ligands were more successful at reducing nicotinamide pink than nitrite pink. As storage time increased, samples became more pink and the addition of ligands was only successful in delaying this affect. One of the most effective ligands, DTPA, reduced the sample CIE a* value 31.7% when tested alone and 30.8% in the presence of nicotinamide. NICHEM was also effectively reduced by DTPA. In general, 50 ppm of added ligand was sufficient to produce a significant reduction in pinking.