Effect of Granule Size and Amylose Content on the Functional, Thermal, and Digestive Properties of Cassava and Yam Starch Blends

ABSTRACT Blending starches with different properties has gained importance in developing materials with a wide range of functionalities. This study assessed the correlation of granule size and amylose content with the techno‐functional, thermal, and digestive properties of cassava (CS) and yam (YS) starches and their blends at different proportions (75:25, 50:50, and 25:75, respectively). CS, characterized by small granules (4.5–21 µm) and a low amylose content (28.39%), exhibited a lower gelatinization temperature, lower resistant starch (RS) content, higher peak viscosity, and higher swelling power. YS, with granules 1.7 times larger than CS and a high amylose content (40.32%), showed a higher RS content and gelatinization temperature, but lower viscosity. The addition of YS significantly decreased the rapidly digestible starch (RDS) content, reducing it from 18.03% in CS to 4.95% in the blends with the highest YS proportion (CS25‐YS75). At the same time, a significant increase in RS was observed, rising from 29.96% in CS to 72.45% in the same blend, demonstrating a favorable effect of YS on the digestibility profile. Intermediate behaviors were observed in the techno‐functional properties: viscosity decreased as the YS proportion increased, but higher swelling was obtained at most temperatures evaluated. Thermal analysis revealed the presence of two peaks in the blend thermograms, reflecting the contributions of each starch. These results highlight the complex interaction between granule size and amylose content and emphasize the potential of starch blend design as a strategy to develop ingredients allowing the adjustment of functional and digestive properties of starches based on blend proportions.