Ultrasound-induced modulation of structural organization and in vitro digestibility in highland barley starch–ferulic acid complexes

The ultrasonic treatment was more likely to form V-shaped complexes. • UT enhanced the thermal stability of the complex. • UT significantly enhanced the anti-digestive property of the complex. This study aimed to investigate the effects of complexes formed by ultrasonicated highland barley starch (UHS) and ferulic acid (FA) at concentrations of 1% to 5% on the functional properties and digestive characteristics of starch. The XRD results showed that UHS formed more V-shaped crystal structures with FA, and the maximum amount of FA increased from 3% to 5%. Fourier transform infrared spectroscopy demonstrated that it enhanced the crystallization and hydrogen bond interaction of UHS with FA. The 1 H NMR spectrum of the complex revealed a more pronounced low-field shift, confirming that ultrasonic treatment significantly enhanced the interaction between starch and FA. This results in higher crystallinity, more complex structural density, and superior viscoelastic and thermal properties, enhancing anti-digestibility and increasing anti-starch content from 20.69% to 28.22%. UT effectively modulates the complex's physicochemical and digestive properties, suggesting potential applications in functional highland food development. Schematic diagram of the experimental procedure. Download: Download high-res image (263KB) Download: Download full-size image