Presalting Condition Effects on the Development of Pink Color in Cooked Ground Chicken Breasts.

The effects of presalting conditions (storage temperature and duration) with/without sodium tripolyphosphate (STPP) on the color and pigment characteristics of cooked ground chicken breast were investigated. Meat mixtures containing 2% NaCl (control) or 2% NaCl and 0.5% STPP (STPP treatment) were stored for 0, 3, 5, 7, and 10 d at 2°C or 7°C, followed by cooking to 75°C, and cooling and storage at 2°C-3°C until further analysis. The treatment was the most effective on the pink color defect of all independent variables. The effect of storage temperature was only observed on CIE L* values and percentage myoglobin denaturation (PMD). The control was redder than the STPP treated samples and the CIE a* values increased (p<0.05) from 0 to 5 d in the control and STPP treated samples. Compared to the STPP treatment, the control exhibited increased reducing conditions (more negative oxidation reduction potential), lower undenatured myoglobin, and greater PMD. No differences in the cooking yields of the control and STPP-treated samples were observed for various storage durations. Products with STPP showed higher (p<0.05) pH values than those without STPP, but no differences (p>0.05) in PMD were observed over the storage period in the control and STPP treated samples, except for day 0. Thus, STPP is effective at reducing the pink color in cooked chicken breasts. In addition, presalting for longer than 5 d resulted in increased pink color of the cooked chicken breasts.

Effect of NaCl Concentration and Cooking Temperature on the Color and Pigment Characteristics of Presalted Ground Chicken Breasts.

This study was conducted to determine the effects of NaCl concentration and cooking temperature on the color and pigment characteristics of presalted ground chicken breasts. Four treatments with different salt concentrations (0%, 1%, 2%, and 3%) were prepared and stored for 7 d prior to cooking. Each sample was cooked to four endpoint temperatures (70°C, 75°C, 80°C, and 85°C). The salt concentration affected the color and pigment properties of the cooked ground chicken breasts. As the salt concentration increased, the cooking yield and residual nitrite content also increased. However, the samples with 1%, 2%, and 3% NaCl showed similar nitrosyl hemochrome and total pigment contents. Among the products containing salt, the samples with 3% NaCl showed the lowest percentage myoglobin denaturation (PMD) and the lowest CIE a* values. The cooking temperature had limited effects on the pigment properties of cooked ground chicken breasts. The oxidation-reduction potential and residual nitrite contents increased with cooking temperature, while the PMD, nitrosyl hemochrome, total pigment contents and CIE a* values were similar in the samples cooked at different temperatures. These results indicated that the addition of up to 2% salt to ground chicken breasts and storage for 7 d could cause the pink color defect of cooked products. However, the addition of 3% NaCl could reduce the redness of the cooked products.

Mechanical Grinding Preparation and Characterization of TiO2-Coated Wollastonite Composite Pigments.

TiO2-coated wollastonite composite pigments were prepared by the mechano-chemical grinding of wollastonite and TiO2 powder together in a wet ultrafine stirred mill. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and infrared spectra were used to investigate the microstructures and morphologies of the composite and the reaction mechanism. The results indicate that the TiO2-coated wollastonite composite pigments have similar properties to titanium dioxide pigment, showing much better properties than dry and wet mixing of wollastonite and TiO2. The hiding power of TiO2-coated wollastonite composite pigments (45% TiO2) is 17.97 g/m², reaching 81.08% of titanium dioxide. A firm combination between wollastonite and TiO2 is obtained through a surface dehydroxylation reaction during the mechano-chemical method.

Effects of Short-Term Presalting and Salt Level on the Development of Pink Color in Cooked Chicken Breasts.

The objective of this study was to determine the effects of short-term presalting on pink color and pigment characteristics in ground chicken breasts after cooking. Four salt levels (0%, 1%, 2%, and 3%) were presalted and stored for 0 and 3 d prior to cooking. Cooking yield was increased as salt level was increased. However, no significant differences in pH values or oxidation reduction potential (ORP) of cooked chicken breasts were observed. Cooked products with more than 2% of salt level had less redder (lower CIE a* value) on day 3 than on those on day 0. As salt level was increased to 2%, myoglobin was denatured greatly. Myoglobin denaturation was leveled off when samples had 3% of salt. With increasing salt levels, residual nitrite contents were increased while nitrosyl hemochrome contents were decreased. These results demonstrate that salt addition to a level of more than 2% to ground meat may reduce the redness of cooked products and that presalting storage longer than 3 d should be employed to develop a natural pink color of ground chicken products when less than 1% salt is added to ground chicken meat.