Dialdehyde starch cross-linked yeast protein gels for dysphagia management: Structure, IDDSI classification and directional peptide design

To address food security challenges, developing sustainable edible protein products is crucial. In this study, dialdehyde starch (DS) effectively cross-linked yeast protein (YP), and an adjustable hydrogel with texture characteristics was developed, which was suitable for dysphagia diets. The YP solution after ultrasonic treatment was cross-linked with DS of different concentrations (2.5%, 5%, 7.5%, 10%). The results demonstrated that DS exerted a significant concentration-dependent regulatory effect on YP conformation. When the DS concentration increased from 2.5% to 5%, the YP conformation exhibited an unfolding-slight shrinkage transition. Further increasing the concentration to 10% induced more pronounced conformational unfolding. During this process, DS transitioned from an initially dispersed state to a stacked arrangement, accompanied by strengthened intermolecular interactions, leading to a continuous decline in helicity and crystallinity with increasing concentration. According to the IDDSI framework, the YP-DS system exhibited Type 5 gel properties. During the digestion of YP, DS regulated the directional release of small molecules with low molecular weight peptides. This study demonstrated the potential of ds cross-linked YP gel as a novel, sustainable, safe and nutritious structurally modified food, providing a practical solution for the dietary management of patients with dysphagia. • Dialdehyde starch exhibited interfacial stabilization effects on yeast protein. • Electrostatic interactions served as the key force for the cross-linked networks. • The conformational regulation by dialdehyde starch showed dose-dependent trend. • Dialdehyde starch showed modulation properties on the yeast protein digestibility.