Pink Color Development in Turkey Meat as Affected by Nicotinamide, Cooking Temperature, Chilling Rate, and Storage Time

Limiting Pink Discoloration in Cooked Ground Turkey in the Absence or Presence of Sodium Tripolyphosphate Produced from Presalted and Stored Raw Ground Breasts

The effects of pink inhibiting ingredients (PII) to eliminate the pink color defect in cooked turkey breast produced from presalted and stored raw ground turkey in the absence or presence of sodium tripolyphosphate (STP) were examined. Ground turkey breast was mixed with 2% sodium chloride and vacuum packaged. After storage for 6 d, ten PII were individually incorporated without or with added STP (0.5%) as follows: none (control), citric acid (CA; 0.1%, 0.2%, 0.3%), calcium chloride (CC; 0.025%, 0.05%), ethylenediaminetetraacetic acid disodium salt (EDTA; 0.005%, 0.01%), and sodium citrate (SC; 0.5%, 1.0%). Treatments were cooked at a fast or slow cooking rate, cooled, and stored before analysis. All PII tested were capable of lowering inherent pink color compared to the control (No STP: CIE a* pooled day reduction of 23.0%, 5.2%, 12.6%, and 12.6% for CA, CC, EDTA, and SC, respectively; STP: reduction of 21.5%, 17.4%, 6.0%, and 18.2% for CA, CC, EDTA, and SC, respectively). For samples without STP, fast cooking rate resulted in higher CIE a*. However, slow cooking resulted in more red products than fast cooking when samples included STP. Presalting and storage of ground turkey caused the pink discoloration in uncured, cooked turkey (CIE a* 6.24 and 5.12 for without and with STP). This pink discoloration can be decreased by inclusion of CA, CC, EDTA, or SC, but incorporation of CA decreased cooking yield. In particular, the addition of SC may provide some control without negatively impacting the cooking yield.

The Effects of Addition Timing of NaCl and Sodium Tripolyphosphate and Cooking Rate on Pink Color in Cooked Ground Chicken Breasts

The current study investigated the effects of timing of NaCl (2%) and sodium tripolyphosphate (STPP, 0.5%) addition and cooking rates on color and pigment properties of ground chicken breasts. Four treatments were tested as follows: treatment 1, no NaCl and STPP added and stored for 7 d; treatment 2, NaCl+STPP added on 0 d and stored for 7 d; treatment 3, NaCl added on 0 d and STPP added on 7 d; and treatment 4, stored for 7 d and NaCl+STPP added. All samples were cooked at a fast (5.67°C/min) or slow cooking rate (2.16°C/min). Regardless of the timing of NaCl and STPP addition, reflectance ratios of nitrosyl hemochrome, cooking yield, pH values, oxidation-reduction potential, and percent myoglobin denaturation were similar (p>0.05) across treatments 2, 3, and 4. The highest CIE a* values were observed in treatment 4 (p<0.05), while treatment 2 was effective in reducing the redness in cooked chicken products. The fast cooking rate resulted in lower CIE a* values and higher CIE L* values and cooking yield in cooked chicken breasts compared to the slow cooking rate. Our results indicate that adding NaCl and STPP to meat, followed by storing and cooking at a fast rate, may result in inhibiting the pink color defect sporadically occurred in cooked ground chicken breasts.

Evaluation of induced color changes in chicken breast meat during simulation of pink color defect

The objective of the study was to establish a pink threshold and simulate the pink defect in cooked chicken breast meat with treatment combinations that would induce significant changes in the color of raw and cooked meat. The subjective pink threshold used in judging pink discoloration was established at a* = 3.8. Samples of three color groups (normal, lighter than normal, and darker than normal) of boneless, skinless chicken breast muscles were selected based on instrumental color values. The in situ changes were induced using sodium chloride, sodium tripolyphosphate, sodium erythorbate, and sodium nitrite at two levels: present and not present. Fillets in all treatments were subjected to individual injections, followed by tumbling, cooking, and chilling. Samples were analyzed for color [lightness (L*), red/green axis (a*), yellow/blue axis (b*)] and reflectance spectra. Simulation of the pink defect was achieved in eight of the 16 treatment combinations when sodium nitrite was present and in an additional two treatment combinations when it was absent. Pinking in cooked samples was affected (P < 0.05) by L* of raw meat color. Results confirmed that it was possible to simulate the undesired pinking in cooked chicken white meat when in situ conditions were induced by sodium chloride, sodium tripolyphosphate, and sodium nitrite. The continuation of the simulation study can aid in developing alternative processing methods to eliminate potential pink defects.

Inhibition of pink color development in cooked, uncured turkey breast through ingredient incorporation

Nonmeat ingredients were tested for their ability to inhibit pink color (which consumers associated with undercooking) in turkey breasts with and without added pink color generating agents (1.0% nicotinamide; 20, 100 ppm nitrite). Nonmeat ingredients included: trans 1,2-diaminocyclohexane-N,N,N',N' tetraacetic acid monohydrate (CDTA), diethylenetriamine pentaacetic acid (DTPA), ethylenedinitrilotetraacetic acid disodium salt (EDTA), and nonfat dried milk (NFDM). Ingredients were evaluated at two (1%, 2% NFDM) or three different levels (50 ppm, 100 ppm, 200 ppm; EDTA, DTPA, and EDTA), over three storage times (1, 4, 21 d), and after 2 min of exposure to light and air. Whole muscle turkey strips were injected with a 20% treatment solution. Product was tumbled and heat processed to an internal temperature of 80 C. Turkey muscle strips containing ingredients without pink color generating agents were less red and lighter than controls. In most cases, 50 ppm of added EDTA, CDTA, or DTPA was sufficient to reduce pinking. Ingredients were more effective against nicotinamide- than nitrite-generated pink. Overall, ingredients delayed onset of pink color associated with storage time. In general, DTPA was the most effective of the test ingredients. However, as NFDM is both effective at reducing the pink defect and approved as a nonmeat ingredient, processors can incorporate this ingredient for the benefit of reducing this defect. Future studies should determine how NFDM achieves this reduction.

Inhibition of pink color development in cooked, uncured ground turkey through the binding of non-pink generating ligands to muscle pigments

The pink color defect in cooked, uncured turkey is a sporadic problem that can result in economic loss and consumer dissatisfaction. Fourteen ligands were tested in ground turkey samples for their ability to reduce pink color development in control samples and in the presence of 150 ppm sodium nitrite or 1.0% nicotinamide (pink color producing agents). The 14 ligands evaluated were: 3-amino pyridine (AP), 4-benzoylpyridine (BP), diethylenetriamine pentaacetic acid (DA), ethylenedinitrilo-tetraacetic acid disodium salt (EA), 2,3 dihydroxybenzoic acid (DB), 3-ethyl pyridine (EP), trans 1,2-diaminocyclohexane-N,N,N',N' tetraacetic acid monohydrate (HA), calcium reduced nonfat dried milk (NM), 2,3 phthalic acid (PA), 3-picoline (PC), pyrrole (PY), pyridazine (PZ), pyridinedicarboxcylic acid (YA), and pyrazinedicarboxcylic acid (ZA). All ligands were incorporated into ground turkey at 0.20 mg/g (meat weight basis) except for NM (30 mg/g). Color was evaluated using a reflectance spectrophotometer to measure pigment changes (nicotinamide hemochrome, nitrosohemochrome) and with a chroma meter to determine CIE L* a* b* values. Reduction in pink color development was apparent with the addition of the ligand alone and in the presence of sodium nitrite and especially nicotinamide. The four most effective ligands tested were DA, EA, HA, and NM. In general, pink color reduction was highest in the ligand only and the ligand plus nicotinamide samples as was observed by CIE a* and nicotinamide hemochrome value reductions.

Effect of background color, sample thickness, and illuminant on the measurement of broiler meat color

The effects of sample thickness (0.5, 1.0, and 1.5 cm), background color (white, pink, green, and gray), and illuminant (D-65, A, and F) on color measurement of broiler tissue were determined. Color values from the anterior portions of the two Pectoralis superficialis muscles were not different from each other, allowing one to be used as a control for the other. Light penetrated the thinner posterior portions of the muscle and was reflected by the white background, producing different L*, a*, and b* values when compared to the thicker anterior portion of the muscle. These changes could alter or mask color changes in the tissue. Light penetrated 0.5 cm thick sliced breast, ground breast, and ground thigh samples and was reflected by the background in large enough quantities to cause color differences (P < 0.05) when both sample thickness and background colors were compared. White and pink backgrounds reflected the largest amount of light, followed in decreasing order by green and gray. The light reflected by background decreased as sample thickness increased from 0.5 to 1.0 cm and no differences due to reflection occurred in the 1.5 cm thick samples. Background reflection can prevent measurement of true sample color. The three illuminants produced different (P < 0.05) color values depending on the major wavelength characteristics of each illuminant. Illuminant choice should depend on wavelength characteristics of the illuminant, sample color, and the color values to be measured.