New Insights into Wax Crystal Networks in Oleogels
Wax-based oleogels are a large category of oleogels where waxes form a continuous crystal network capable of structuring liquid oil within. Natural wax oleogelators are of particular interest owing to the low concentration of wax required to form a gel, the stability of the gels that they create, the wide range of properties the gels can attain, and the natural origin of the wax gelators. The gel’s microstructure, rheological properties and oil binding capacity are dependent on both the properties of the wax itself and the processing conditions used in gel production. Characteristic wax traits, primarily the chemical composition, can be used to predict the properties of a wax crystal network in an oleogel. The uniqueness of each wax means that no two oleogels will be identical. Varying the processing parameters, including the variation of cooling rates and application of different shear rates, can be used to alter the physical properties and potentially tailor a crystal network for the desired application. Wax crystal networks in oleogels continue to be investigated thoroughly, giving rise to new analytical methods that are constantly improving analysis. Specifically, recent works have used new methods that have provided new insights into the morphology and precise composition of natural waxes. As a natural source of structured, unsaturated lipids, wax-based oleogels have applications in pharmaceuticals, cosmetics and as a solid fat replacement in foods. However, the latter application is limited by regulations that do not yet allow the unrestricted use of all natural waxes in foods.