Understanding the influence of β-glucan-based superabsorbent hydrogel on the digestibility of wheat starch: Gelatinization, rheological and structural properties

This study aims to evaluate the effects of β-glucan-based superabsorbent hydrogel (βCHY) on wheat starch digestibility and elucidate the underlying mechanism. The results revealed that the incorporation of βCHY led to a significant reduction in rapidly digestible starch content of wheat starch from 71% to 44%, while concurrently increasing the levels of slowly digestible starch and resistant starch in a dose-dependent manner. From a mechanistic perspective, incorporating βCHY into wheat starch notably affected their pasting behavior and influenced the rheological properties and gel strength of resulting gels. Moreover, the addition of βCHY increased the relative crystallinity, short-range ordered degree (R1047/1024), molecular order (the full width at half maximum at 480 cm−1), and thermal stability of the starch, suggesting the formation of a more stable and ordered structure. Furthermore, the wheat starch-βCHY gel complexes exhibited large, discrete layered structures with thicker layer walls, accompanied by interspersed filament-like structures. These structural alterations may collectively contribute to the reduced digestibility of wheat starch. These findings confirmed the positive effects of βCHY on the starch digestibility, offering valuable insights into the development of innovative starch-based foods with slow digestion characteristics. [Display omitted] •β-glucan of highland barley was extracted to prepare superabsorbent hydrogel (βCHY).•Starch granules were dynamically encapsulated into the empty cavity of swollen βCHY.•βCHY increased the pasting viscosity and thermal stability of wheat starch.•βCHY addition greatly affected the gel network structure of wheat starch.•βCHY exhibited the significantly efficacy in reducing wheat starch digestibility.