Influence of Gluten and Modified Gluten on the Physicochemical and Digestive Properties of Cassava Starch

This study investigated the effects of natural glutenin and its derivatives (alkali-treated pH-Glu, enzymatically degraded GPH, and malic acid-modified MA-Glu) on the physicochemical properties and digestibility of cassava starch (CS) using rheological analysis, X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy. The results demonstrated that pH-Glu, by disrupting disulfide bonds and exposing polar groups, significantly enhanced the viscoelasticity of CS, increased its relative crystallinity, and reduced amylose leaching to 14.65% (complex index=25.06%). Meanwhile, low-molecular-weight peptides derived from GPH build a stable, ordered structure and a physical barrier with cassava starch (CS) through extensive intermolecular interactions. This compact network lowers the rapidly digestible starch (RDS) fraction to 58.68% and raises the resistant starch (RS) level to 27.97%. In contrast, MA-Glu, characterized by high solubility (60.5%) and strong intermolecular interactions (complex index=39.19%), induced the formation of a denser CS network with elevated crystallinity (11.5%) and further reduced digestibility (RDS=51.21%, RS=29.79%). This study established a theoretical foundation for the development of customized staple food formulations designed for individuals with diabetes and obesity. Additionally, it explores new avenues for the application of functionalized starch-based foods, with a particular focus on texture modification (CS-pH-Glu), sustained energy release (CS-GPH), and improved resistance to digestion (CS-MA-Glu).