The influence of wax-based oleogelators on microstructure evolution, rheology and diffusion

Artikel i vetenskaplig tidskrift, 2026

In plant-based products made to mimic meat it is sought after to include fat to enhance flavor and texture based on healthy plant-based oils. Oleogels have gained interest as way of structuring oils. However, understanding how the crystalline network affects long-term stability and oil mobility remains limited. In this study, rapeseed oil oleogels containing 10 % (w/w) of either candelilla wax, beeswax, or rice bran wax were investigated. We combined low-strain rheo-microscopy, differential scanning calorimetry (DSC), and fluorescence recovery after photobleaching (FRAP) to explore the evolution of microstructure, thermal transitions, viscoelastic properties, and local oil diffusion – an approach not previously applied to wax-based oleogels. Candelilla wax formed a dense homogenous network with small crystals and beeswax had longer needle-like aggregated structures. Both candelilla and beeswax showed one crystallization peak in DSC and a sharp increase in storage modulus during rheo-microscopy explained by their network structure. Rice bran wax had a mixture of larger spherulite structures and smaller crystals. Two distinct crystallization events were observed in DSC and rheo-microscopy for rice bran wax corresponding to the formation of large spherulites and subsequently smaller interspersed crystals. FRAP showed that candelilla wax with its dense homogenous structure had the largest retardation rate independently of observation region. The diffusion in the crystal region was fastest in the rice bran wax which indicates a loosely packed crystal structure in the spherulites.