Oleogels are semi-solid materials containing a large fraction of liquid oil entrapped in a network of structuring molecules. In the food industry, these formulations can be used to mimic fats and to deliver bioactive compounds. In the last decade, there has been increasing interest in these structures, not only from a scientific point of view, i.e., studying new molecules, methodologies for gelification, and new structures, but also from a technological point of view, with researchers and companies exploring these structures as a way to overcome certain challenges and/or create new and innovative products. One of the exciting applications of oleogels is the delivery of functional molecules, where the incorporation of oil-soluble functional compounds can be explored not only at the macroscale but also at micro- and nanoscales, resulting in different release behaviors and also different applications. This review presents and discusses the most recent works on the development, production, characterization, and applications of oleogels and other oleogel-based systems to deliver functional molecules in foods.

This study investigates how lipid crystalline structures in emulsions evolve during digestion, aiming to inform functional food design and potentially modulate lipid digestion. Using synchrotron-based X-ray diffraction, we monitored real-time structural transformations of lipids during in vitro digestion of 16 emulsions with varied lipid phases and emulsifiers, revealing rapid, composition-dependent transformations. These changes include lamellar packing changes and the emergence of different polymorphic forms originating from digestion products, as early as the first two minutes of lipolysis. Palm-based systems showed a reduction in native β-polymorphs, while wax-based systems retained β'-forms. Lamellar packing spacings shifted towards 62 Å and 48 Å across all systems, suggesting similar structural adaptation, regardless of the original sample composition. Modified starch and hydroxypropyl methylcellulose as emulsifiers reduced the extent of lipolysis. These findings offer insight into lipid self-assembly during digestion and support the development of functional foods targeting metabolic health.