Physical and Oxidative Stability of Oleogels During Storage

Interest in oleogels (or organogels) as alternatives to conventional solid fats is growing. Therefore, for their practical applications, it is important to understand their physical and oxidative stability during storage. Oleogels undergo changes in physical properties through polymorphic transitions, changes in the number and morphology of crystals, and changes in connections between crystals during storage, which may result in release of oil and phase separation. Oxidation of oleogels is inevitable due to the presence of polyunsaturated fatty acids in oil. The physical and oxidative stability of oleogels and oleogel-containing foods must be acceptable by manufacturers and consumers. This chapter discusses the methods to determine physical and oxidative stability, the stabilities of different types of oleogels, and strategies to improve them. In general, many oleogels were found to have satisfactory physical stability and higher oxidative stability than the corresponding oil. However, some oleogels need to be improved. In addition, the stability of oleogels should be examined compared to the conventional solid fats to be replaced. Since the physical and oxidative stabilities of oleogels are affected by many factors such as the detailed composition of oleogelator, type of oil, preparation parameters, and storage conditions, more comprehensive studies are needed for better understanding of the factors affecting the stability of oleogels.