Physical Properties of Candelilla Wax, Monoacylglycerols, and Fully Hydrogenated Oil Oleogels

Oleogels have been studied in the past decade due to their potential to replace saturated fat in foods. Oleogelators have been mostly studied alone or in binary systems. Sometimes a single oleogelator cannot achieve all the technological properties necessary for a specific food application. Thus, the aim of this work was to investigate the interaction between candelilla wax (CLX), monoacylglycerols (MAG), and a fully hydrogenated oil (hardfat [HF]) in soybean and high-oleic sunflower oils and to evaluate their physical properties. The concentration of the total oleogelator was between 5% and 10%, from pure CLX (5%), sample OP, up to many combinations of MAG, HF, and CLX samples O1, O2, O3, O4, O5, and O6. Samples were evaluated according to their microstructure, melting properties, rheological behavior, hardness, oil-binding capacity (OBC), and thermal stability. Results showed that the addition of MAG and HF to CLX created a softer gel but improved its rheological properties. Changes in the physical properties were related to the various proportions of CLX, MAG, and HF rather than the overall concentration of structuring agents. For example, for a total concentration of 5% of the structuring agent, a decrease in the CLX concentration from 5% to 3% and the addition of HF and MAG resulted in a softer crystalline network. Increasing the overall concentration of oleogelators by increasing the amount of HF and/or MAG and maintaining the concentration of the CLX constant did not improve the hardness of the gel. This study showed that at least 3% of CLX must be added to the system to obtain a semisolid material independently of the amount of MAG and/or HF added.