Gallic acid-reinforced Rana chensinensis ovum protein isolates-Gellan gum thermally reversible emulsion gel: Insight of the structure and potential applications in dysphagia management

Abstract

This study investigated the impacts of gallic acid (GA) on the structural and functional properties of Rana chensinensis ovum protein isolate (RCOPI)-gellan gum (GG) Pickering emulsion gels. An innovative Pickering emulsion gel system (RGAGG-eg) was successfully developed. Mechanistic studies revealed that GA may act as a molecular bridge, utilizing its own phenolic hydroxyl and carboxyl groups to enhance the interaction of RCOPI-GG through hydrogen bonding. This resulted in a 21.23 % reduction in the particle size of the RGAGG-cx, indicating that a denser crosslinked network was obtained. The particle size of the RGAGG-em droplets is reduced by 32.39 % as a result of the more closely bound complex particles being more securely adsorbed on the surface of the oil droplets. The helical change of the GG structure caused the emulsion to gel during the heating phase. CLSM and SEM confirmed GA-induced microstructural compaction, while rheological analysis demonstrated improved gel strength (G' > G''). The RGAGG-eg met IDDSI levels 4 pureed properties ideal for dysphagia management. As a proof-of-concept, the system achieved 98.26 % β-carotene encapsulation efficiency with 69.81 % bioaccessibility. Those results suggested the RGAGG-eg demonstrated dual functionality as a nutrient carrier and texture-modified food.