No abstract

No abstract

Functional and rheological properties of proteins from frozen turkey breast meat with different ultimate pH at 24 h postmortem (pH(24)) have been studied. Sixteen breast fillets from Hybrid Tom turkeys were initially selected based on lightness (L*) values for each color group (pale, normal, and dark), with a total of 48 breast fillets. Further selection of 8 breast samples was made within each class of meat according to the pH(24). The average L* and pH values of the samples were within the following range: pale (L* >52; pH ≤5.7), normal (46 < L* < 52; 5.9 < pH <6.1), and dark (L* <46; pH ≥6.3), referred to as low, normal, and high pH meat, respectively. Ultimate pH did not cause major changes in the emulsifying and foaming properties of the extracted sarcoplasmic and myofibrillar proteins. An SDS-PAGE profile of proteins from low and normal pH meat was similar, which revealed that the extent of protein denaturation was the same. Low pH meat had the lowest water-holding capacity compared with normal and high pH meat as shown by the increase in cooking loss, which can be explained by factors other than protein denaturation. Gel strength analysis and folding test revealed that gel-forming ability was better for high pH meat compared with low and normal pH meat.Dynamic viscoelastic behavior showed that myosin denaturation temperature was independent of pH(24). Normal and high pH meat had similar hardness, springiness, and chewiness values as revealed by texture profile analysis. The results from this study indicate that high pH meat had similar or better functional properties than normal pH meat. Therefore, high pH meat is suitable for further processed products, whereas low pH meat may need additional treatment or ingredient formulations to improve its functionality.

Chicken dark meat has been considered as a major underused commodity due to the increasing demand for further-processed breast meat products. One option to increase the utilization of chicken dark meat is to extract myofibrillar proteins and separate them from fat and pigments to enhance their application for the preparation of further-processed meat products. The objective of the current study was to determine the effect of pH, in the range of 10.5 to 12.0, on the alkaline solubilization process of chicken dark meat. Aspects studied were the effect of the alkali-aided process on protein content, lipid composition, lipid oxidation, and color characteristics of the extracted meat. Each experiment and each assay were done at least in triplicate. Lipid content of the extracted meat showed a 50% reduction compared with the chicken dark meat. Neutral lipids were reduced by 61.51%, whereas polar lipids were not affected by the alkali treatments. There was a higher amount of TBA reactive substances observed in the extracted meat compared with chicken dark meat, indicating that extracted meat was more susceptible to oxidation. Long-chain polyunsaturated fatty acids (22:4n-6, 20:3n-3, 20:5n-3, 22:5n-3, and 22:6n-3), which were detected only in the polar lipids, were responsible for increasing lipid oxidation susceptibility of extracted meat compared with chicken dark meat. Alkali-aided extraction of chicken dark meat lightened the color of the meat. The redness, yellowness, and total heme pigments in extracted meat significantly decreased by 83, 11, and 53%, respectively, compared with chicken dark meat. Even though this process did not remove polar lipids, based on our early findings, the extracted meat had considerable physicochemical and textural properties for product preparation compared with those of raw dark meat. Hence, alkali recovery of protein can be considered a potentially useful method to increase the utilization of dark chicken meat.

No abstract