Effects of cross-linked/acetylated tapioca starches on the gelling properties, rheological behaviors and microstructure of myofibrillar protein gels: Perspective on molecular interactions and phase transition

The present work mainly investigated the changes of gel characteristics, rheological properties and ultrastructure of myofibrillar protein (MP) gels with varying amounts (2, 4, 6, and 8 %, w/w) of cross-linked tapioca starch (CTS) or acetylated tapioca starch (ATS). The findings showed that CTS or ATS notably improved the gelling characteristics (such as gel strength and water retention) of mixed MP gels in a dose-dependent manner (P < 0.05), which was clearly verified by the results of rheological behavior tests under different modes. Moreover, compared to ATS, CTS rendered higher gel strength and promoted the formation of a more uniform and smoother mixed MP gel matrix, which was mainly attributed to the higher peak viscosity of CTS. Furthermore, the images of iodine staining indicated that in mixed MP gels, the continuous phase supported by MP was gradually transited to being starch supported as the amounts of CTS or ATS increased between 2 % and 8 %. Additionally, hydrophobic interactions and disulfide bonds were the principal chemical forces of mixed MP gels, which could promote the occurrence phase transition. Briefly, our present work provided some vital understanding of the molecular interactions between MP and modified tapioca starches, which could efficiently modulate the quality profiles of meat products.