Effect of Heat Treated Resistant Corn Starch on Gel Properties and 3D Printing Properties of Myofibrillar Protein Composite Emulsion Gel

The present study investigated the effects of resistant corn starch (RCS) heat-treated at various temperatures (25, 40, 60, 80, and 100 ℃) on tilapia myofibrillar protein (MP) emulsion gel viscoelastic properties, particle size distribution, microstructure, centrifugal stability, Raman spectroscopy and three-dimensional (3D) printing characteristics. The results showed that the RCS heat-treatment temperature significantly modulated the hydrophobic interactions, thereby affecting the emulsion gel rheology and structural stability. When the RCS heat treatment temperature was 40 ℃, RCS swelled moderately, and the emulsion gel exhibited optimal performance, demonstrating pseudoplastic flow behavior, high elasticity, and a uniform particle size distribution. Apparent viscosity, storage modulus (G'), thixotropic recovery rate, and particle size uniformity increased significantly, thus enhancing the gel network structure and stability. This formulation exhibited excellent 3D printing extrudability and self-supporting ability, maintaining its structural integrity even after astaxanthin loading. Raman spectroscopy revealed that hydrophobic forces primarily governed gel network formation without covalent bond involvement. When the RCS heat treatment temperature exceeds 60 ℃, the the linear starch in the RCS leaches out, causing decrease in apparent viscosity and shear stress.Collectively, this study elucidated the mechanism through which heat-treatment temperature regulated RCS to influence RCS-MP emulsion gel stability. The findings showed that 40 ℃ was the optimal temperature for enhancing rheology and 3D printing performance, thereby providing a crucial theoretical basis for developing high-precision, personalized 3D printing food-grade inks and expanding RCS applications in functional foods.