Modulating Starch Properties Through Hydrothermal Treatment and Psyllium Fibre Supplementation: Influence of Amylose Contents

ABSTRACT Although the individual effects of hydrothermal treatment, psyllium fiber, and amylose content on starch properties are well understood, their combined interactions remain largely unexplored. This study investigated the impact of heat moisture treatment (HMT) and annealing (ANN), combined with 3% psyllium husk fiber (PHF), on the structural, rheological, and digestibility properties of maize starch with varying amylose content. The starch samples were analyzed for crystallinity, viscosity, and in vitro digestibility. Frequency sweep and FTIR spectra were also determined. Waxy and normal maize starch showed typical A‐type diffraction pattern, while high‐amylose starch exhibited B‐type diffraction pattern. HMT‐treated starches had significantly ( p ≤ 0.05) lower peak and final viscosities, while ANN‐treated starches exhibited higher viscosities. HMT and ANN treatments generally increased G', regardless of fiber addition, except for waxy maize starch. Hydrothermal treatments alone had minimal impact on slowly digested starch (SDS) and resistant starch (RS) content, but psyllium significantly increased SDS and RS levels. Findings from the study suggest that combining HMT and ANN with PHF supplementation can significantly modulate starch digestibility, making them suitable for functional food applications with potential health benefits such as diabetes management and improved gut health. Future research should focus on the application of the starch blends in product formulations, as well as the evaluation of their shelf life and sensory properties in the newly developed products.