Ultrasound-modified soy protein-hyaluronic acid conjugates for swallowing-friendly high internal phase pickering emulsion gels: structure, properties, and applications

Abstract

With the increasing global aging population, there is a growing demand for safe and nutritious specialized foods tailored to individuals with dysphagia. However, designing foods with suitable texture, stability, and swallowability remains a significant challenge. This study explores the use of high-intensity ultrasound (HIU)-modified soy protein isolate (SPI)/hyaluronic acid (HA) complexes and conjugates to fabricate high internal phase Pickering emulsion gels (HIPPEGs) suitable for dysphagia patients. The formation of the SPI/HA conjugate was demonstrated by SDS-PAGE and degree of grafting. Compared to SPI alone, the HIU-treated conjugate exhibited smaller particle size, higher surface charge, greater surface hydrophobicity, and enhanced structural flexibility, leading to superior emulsifying performance. Rheological analysis confirmed that HIPPEGs stabilized by U-Conjugate possessed higher gel strength. Texture profile and IDDSI tests indicated a soft texture, low adhesiveness, and favorable swallowability—all meeting the requirements for dysphagia diets. LF-NMR and CLSM analyses further revealed uniform water distribution and a dense, homogeneous microstructure. Moreover, U-Conjugate-stabilized HIPPEGs demonstrated potential for in vitro quercetin delivery and suitability for 3D printing applications. In conclusion, this study provides an effective strategy for developing high-performance HIPPEGs with strong potential for application in dysphagia-friendly food design, particularly highlighting their capabilities in nutrient delivery and 3D printing.