Microemulsion gel systems: Formulation, stability studies, biopolymer interactions, and functionality in food product development

Abstract Microemulsion gels (MGs) are nanostructured systems created by the addition of thickening agents/biopolymers to a microemulsion's aqueous or oily phases, offering benefits like improved solubilization, enhanced stability, high encapsulation efficiency, and sustained release with versatile applications in food, pharmaceuticals, and cosmetology. MGs are intricate systems with thermodynamic robustness and controllable rheological characteristics crucial for obtaining high structural integrity and achieving innovative results regarding food product development in diverse areas of food, including colloidal carriers, food packaging, active compound delivery, antimicrobial vectors, and production of biopolymer nanoparticles. Therefore, a comprehensive analysis, hence understanding about MG systems, is needed to identify trends and gaps, helping researchers to identify promising areas for innovation and providing direction for future research. This review offers a comprehensive analysis of MG systems, their characteristics, formulation, formation mechanisms, design approaches, digestion dynamics, and rheological properties. MGs excel in solubilizing hydrophilic and lipophilic bioactives due to their enhanced viscosity and interconnected droplet network within the gel matrix. Despite their advantages, challenges, such as formulation complexity, require further understanding. This article also explores innovative biopolymers, characterization, and extensive applications, while addressing case studies, and emerging trends leveraging the potential of MG systems for enhancing food stability, functionality, and nutritional value.