As the increasing demand for clean-label, plant-based, and functional food systems, bigels, an innovative biphasic structured system composed of both hydrogels and oleogels, have emerged as promising research focus for delivering functional ingredients in the food, pharmaceutical, and cosmetic fields. Plant-based bigels, formulated from edible biopolymers and vegetable oils, represent a sustainable and regulatory-compliant delivery platform. This review critically reviews the recent advances in the structural design and stabilization of plant-based bigels, with an emphasis on the regulation of phase behavior and interfacial interactions. Advanced strategies, including stimuli-responsive gelation, Pickering interfaces, and semi-interpenetrating networks, are explored to improve stability and enable targeted gastrointestinal release. Applications in the delivery of polyphenols, omega-3 fatty acids, lipophilic vitamins, and probiotics are highlighted, underscoring the relationship between structural construction and delivery performance. Furthermore, current challenges and potential solutions concerning stability enhancement, bioavailability improvement, and industrial scalability are outlined. Future research directions are proposed to address existing gaps and to further exploit the potential of plant-based bigels for functional compound delivery.

This review emphasizes key findings regarding nanoemulsions utilized as carriers for fat-soluble vitamins (FSVs). The stability of FSV-loaded nanoemulsions is chiefly determined by the emulsifier type and concentration, carrier oil type, oil composition and concentration, and droplet size. Natural emulsifiers such as saponins, lecithin, and proteins, in conjunction with long-chain triglycerides (LCT) such as olive and corn oils, prove beneficial in enhancing FSVs’ bioavailability. Despite the established effectiveness of nanoemulsions in enhancing FSVs’ stability and bioaccessibility, the safety of FSV encapsulation within nanoemulsions remains incompletely understood. Importantly, relying solely on in vitro studies is inadequate to simulate the actual gastrointestinal behavior of nanoemulsion systems. Future investigations should prioritize encapsulating FSVs in natural emulsifier-stabilized nanoemulsions and incorporate both in vivo and in vitro experiments to explore the gastrointestinal destiny of these delivery systems. This review offers crucial insights for the systematic development of FSV-enriched functional foods utilizing nanoemulsion technology.