Rheological, textural, and structural properties of heat-induced yam starch gels: Effects of high-amylose mung bean starch

Yam starch (YS) has inherently weak gel strength because of its high amylopectin content, which critically restricts its advanced applications in the food industry. This study investigated the effect of incorporating high-amylose mung bean starch (MBS) (0-4%) as a natural modifier on YS gel properties. Results showed that MBS addition dose-dependently enhanced pasting temperature, viscosity, viscoelastic moduli, hardness, chewiness, and thermal stability of YS gels. Microstructurally, it led to a denser gel network with a smoother, more homogeneous nanoscale surface. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analyses indicated that MBS suppressed long-range crystallinity of YS gels but promoted short-range order and formed more junction zones within the amorphous network, resulting in an amorphously reinforced gel matrix. This reinforcement was ascribed to the competitive hydrogen bonding and cross-linking between MBS amylose and YS components. The work provides a green strategy for designing starch-based gels with tunable texture and improved stability for food applications.