Interactions between candelilla wax and saturated triacylglycerols in oleogels

Fully hydrogenated oils or hardfats are low cost and highly available products used in lipid technology while candelilla wax (CLX) is a well-known oleogelator that has been thoroughly studied over the last decade. CLX is capable of making a strong oleogel when used in very low concentrations (similar to 1.5%) while hardfats need to be added in higher concentrations (> 10%) to form a gel. Based on the molecular similarity between hardfats and CLX the aim of this work is to evaluate the use of CLX and various hardfats in combination to form stable oleogels. The hardfats used in this study in combination with CLX were crambe (HCr), palm (HP1), palm kernel (HPk) and soybean (HSb). The total concentration of oleogelator used was 5% and soybean oil was used as the dispersing media. The proportions of 0:1, 0.25:0.75, 0.5:0.5, 0.75:0.25 and 1:0 of CLX:hardfats were studied. HP1 and HCr fats formed a more stable and organized crystal network when used in all blends as shown by a shift towards to lower melting temperatures. However, G' and oil loss were close to CLX only when HP1 was added in small amounts (0.25 and 0.5). The HSb fat presented similarity to CLX only for blend 0.25. HPk did not show any interaction with CLX due to the different triacylglycerol composition of this hardfat compared to the others. These results show that hardfats have the potential to be used in oleogel formulation especially when used in combination with CLX. The use of hardfats is attractive to producers since they are inexpensive and readily available and they can be used to reduce the total amount of CLX in food formulations avoiding the common waxy sensation associated with CLX formulations.