Hydrothermal modification of starch-rich flour blends derived from tubers: Physicochemical and textural impacts on muffin quality

• Annealing resulted in a modified flour blend with enhanced thermal stability and reduced retrogradation tendency. • The results indicate the development of a muffin with good overall acceptability, a porous crumb structure, and favorable expansion capacity using modified tuber flours. • Annealing is a viable hydrothermal technology for modifying binary flour blends for application in baked products. Although tuber flours have attracted significant interest in the food industry, their versatility is limited by various technological constraints during the processing of starch-rich materials. In this context, the present study aims to implement annealing treatments on binary blends of native yam ( Dioscorea alata L. cv. Criollo) and sweet potato ( Ipomoea batatas (L.) Lam. cv. Aurora) flours for their application in the development of a muffin-type baked product. Binary blends were prepared in a wet medium using a 1:1 w/w flour ratio, followed by hydrothermal annealing modification. The modified flour blends were then incorporated as substitutes for wheat flour in muffin formulation. The blending process led to an increase in breakdown and setback viscosity of the pastes, which reduced thermal stability and promoted starch retrogradation in the flours. However, the hydrothermal treatment significantly reduced viscosity profiles (<460 cP), increased the gelatinization onset temperature (>78.69 °C), decreased the differential gelatinization (<10.83 °C), and lowered breakdown viscosity (<2.87 cP), indicating greater stability and structural homogeneity in the starchy material. Additionally, physicochemical analysis revealed a reduction in water absorption capacity, cold water solubility, and swelling power with increasing annealing cycles, leading to the formation of a more stable and porous crumb structure. The incorporation of modified flour blends resulted in a baked product with lower fat content (20.39 - 20.54%) and higher fiber content (2.80-2.92%) compared to the control (NYF). Furthermore, the muffins exhibited good overall acceptability (>6.0) based on expansion volume and chewiness, demonstrating the technological feasibility of using modified yam/sweet potato flour blends in baked product development.