Oral lubrication and flavor release in myofibrillar protein-based emulsion gel fat substitutes: Arginine-regulated interfacial architecture.

To address the health problems arising from excessive intake of traditional fats and the challenges of texture and flavor deterioration in products caused by fat reduction, the present study regulated the structural organization and oral functionality of myofibrillar protein (MP)-based emulsion gels by varying L-arginine (Arg) concentrations (0-15 mmol/L) and oil phase contents (20% and 40%, w/w). From a colloidal perspective, the intrinsic links among interfacial distribution, oral lubrication, and flavor release were systematically elucidated. First, Arg optimized the adsorption and spreading behavior of MP at the oil-water interface, improved the physical stability of emulsions, and achieved the uniform dispersion of small droplets. Second, Arg facilitated the uniformly dispersed small oil droplets in forming a continuous and dense three-dimensional network, enhancing gel strength. This enabled the gel to undergo uniform fragmentation during mastication, facilitating steady oil release and sufficient liberation of flavor compounds. By contrast, excessive Arg or high oil loading disrupted continuous-phase integrity and interfacial stability, resulting in droplet aggregation and diminished sensory performance. Overall, the optimal formulation was determined to be 5 mmol/L Arg combined with 20% oil phase: it achieved excellent interfacial properties and a dense gel structure while reducing the oil phase content, and balanced oral lubricity with flavor release capacity. This study provides an important theoretical basis and technical support for the precise design of MP-based fat-mimicking systems and the synergistic optimization of product quality and flavor.