Effect of Cooling Rate on the Oleogel Properties of Wax–Wax-Hydrolyzate Mixtures

Abstract

AbstractIn this contribution, the effect of cooling rates on a wide compositional range of waxes as oleogel structurants was systematically investigated. The different waxes exhibited varying levels of wax esters (WE), fatty acids (FA), fatty alcohols (FaOH) and hydrocarbons (HC) and were systematically altered by combinations of sunflower wax (SFW), bees wax (BW) and their hydrolyzed variants (SFWh, BWh). By applying slow, medium and high cooling rates, the resulting gel properties were investigated in terms of firmness, calorimetry and microstructure. It was found that the calorimetrical signal is mainly affected by the waxes’ composition. However, due to enlarged dynamic induction times upon crystallization, a shift in dissolution temperature could be observed in heating scans. In our latest work we were able to formulate the degree of homogeneity (DoH), with which it was possible to predict the undercooling in SFW mixtures. The introduction of a novel method emerged for firmness measurements of oleogels treated with the different rates. Thus, it was possible to detect with high sensitivity for all waxes for applied cooling rates, caused by modification of microstructure. Combination of different methods further elucidated that higher rates need to be applied to further scale firmness of oleogels in industrial processes.