Effects of pH on the functional properties of chicken muscle proteins- modified waxy cornstarch blends

Chicken breast muscle powder (CBMP) and modified waxy cornstarch (MWCS) blends were prepared at different pH conditions (pH 4, 5, 6, 7, 8, and 9). The blends were characterized by light microscopy, frequency sweep, flow analysis, and freeze-thaw stability analysis. Light microscopy showed that the blend structure was coarse at pH conditions close to the isoelectric point of protein and became finer with increasing pH. Frequency sweep demonstrated that the blend was more liquid-like with relatively lower storage (G') and loss (G'') moduli as the pH was increased from pH 4 to pH 9. Flow analysis revealed that thixotropy behavior was evident in samples treated at pHs 4 and 5, whereas antithixotropy was shown by those adjusted to pHs 6, 7, 8, and 9. The CBMP-MWCS blends were found to show better freeze-thaw stability at pH 8 that could be attributed to the formation of a highly interactive network structure of CBMP and MWCS.