Increasing the firmness of wax-based oleogels using ternary mixtures of sunflower wax with beeswax:candelilla wax combinations

Authors: Moser, Jill; Hwang, Hong-Sik; Felker, Frederick; Byars, Jeffrey; Peterson, Steven - Steve

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/31/2022
Publication Date: 1/13/2023
Citation: Moser, J.K., Hwang, H., Felker, F.C., Byars, J.A., Peterson, S.C. 2023. Increasing the firmness of wax-based oleogels using ternary mixtures of sunflower wax with beeswax:candelilla wax combinations. Journal of the American Oil Chemists' Society. 100(5):387-402. https://doi.org/10.1002/aocs.12679.
DOI: https://doi.org/10.1002/aocs.12679

Interpretive Summary: This study found that by using mixtures of three waxes with liquid vegetable oil, oleogels with higher firmness and good melting characteristics could be produced in comparison with oleogels made with one or two waxes. Fats such as palm oil, hydrogenated oils, and animal fats, tend to be high in saturated fats which are associated with high blood cholesterol and heart disease. Current nutrition recommendations are to reduce saturated fats in the diet and replace them with vegetable oils that are higher in healthy monounsaturated and polyunsaturated fatty acids. However, replacing fats with oil is difficult to achieve in food products where it is necessary for the oil to be solid at room or refrigerated temperatures, such as margarines, shortenings, icings, fillings, bakery frying fats and even plant-based meats. Oleogels are a promising new technique for creating the texture and functional attributes of solid fats while replacing them with edible liquid oils in foods. Small amounts of natural waxes such as beeswax and candelilla wax (which is produced from Candelilla plant) are useful for combining with vegetable oils to produce oleogels that have similar texture to fats. One way that the firmness of the oleogels can be increased to be more like a fat is to increase the amount of wax used. However, if too much wax is used, it won’t melt when it is consumed and will leave a waxy taste and texture in the mouth. In previous research we discovered that by mixing waxes like beeswax and candelilla wax, oleogels with greater firmness could be produced without needing to use more wax. In this study, we found that by adding a small amount of a third wax, sunflower wax, we could improve firmness and the oleogel strength even more, while still not increasing the total amount of wax or impacting the melting properties. The shape of the wax crystal network changed when waxes were combined, forming smaller crystals and stronger oleogels. Therefore, by mixing waxes, oleogels can be made that are closer to the consistency and melting properties of traditional fats so that they can be replaced in food products to produce healthier foods. This information will be helpful for food companies as they strive to lower the saturated fat content in a variety of food products.

Technical Abstract: Oleogels were prepared with 5% wax in soybean oil using mixtures of beeswax(BW) and candelilla wax (CLW) with ratios of 10:90, 30:70, 50:50, and 60:40BW:CLW, and the same series where 10% of the total wax was substituted withsunflower wax (SFW). The hypothesis that SFW would increase the firmnessof the oleogels without affecting the melting properties was tested. Firmness ofone-wax oleogels decreased from SFW > CLW > BW. Oleogels with 50:50BW:CLW and 60:40 BLW:CLW had equal firmness to pure 5% SFW oleogels.SFW significantly increased oleogel firmness and reduced the softening thatoccurred between 4C and 22C. Increased firmness was also found with ricebran wax and behenyl-behenate (C44) addition, but not with wax esters withchain lengths ranging from 30 to 40 carbons (C30 to C40). By differential scan-ning calorimetry, SFW significantly decreased the melting point of oleogels with10:90 and 30:70 BW:CLW mixtures but significantly increased the melting pointof those with 50:50 and 60:40 BW:CLW mixtures. However, the solid fat con-tent melting curves were not significantly influenced by SFW addition. Theseresults indicate that mixed wax oleogels had greater hardness and elasticity,and that the long chain wax esters contributed by SFW helped to improve thestrength of oleogels without negatively affecting their melting properties.