Oleogels: Innovative formulations as fat substitutes and bioactive delivery systems in food and beyond

Fats and oils provide flavour and texture to food while also promoting satiety. Despite the recommendation to consume primarily unsaturated lipid sources, the liquid state of unsaturated lipids at ambient temperature precludes numerous industrial applications. Moreover, the issue of the adverse effects of trans-fatty acids has become more apparent due to research demonstrating their association with coronary diseases, obesity, and type 2 diabetes. Oleogels are liquid oils encapsulated within a thermoreversible, three-dimensional gel network using oleogelators such as waxes, monoglycerides, phospholipids, and phytosterols. Oleogels have been used extensively in numerous food formulations to reduce the amount of saturated and trans-fatty acids. In recent decades, oleogel research has been active, producing numerous oleogels with desirable characteristics such as thermal resistance, texture, and structural stability. In addition, oleogels have been incorporated into a number of food matrices. In some instances, oleogels in these food products resemble the textural characteristics of products made with conventional hardstock fat, improve dietary nutrition, exhibit high physical and oxidative stability, and have a high oil-binding capacity. These advancements demonstrate the potential of oleogels, but certain disadvantages and a lack of in-depth information on various aspects have delayed their commercialization in the food industry. This narrative review aims to outline the preparation of oleogels, their application in selected food products, their digestibility, other applications of oleogels, such as bioactive delivery in wound healing and antibacterial properties, and the existing challenges in exploring oleogels.