Effect of Storage Time on Wax–Wax–Hydrolyzate Canola Oil Oleogels

Abstract

In this study, two natural waxes, beeswax (BW) and sunflower wax (SFW), are combined with their hydrolyzed variants to deliberately alter the waxes’ composition. The properties of the produced oleogels with different wax inclusion levels (4%, 8%, 12%, and 16% w/w) are investigated after defined intervals (2 days, 7 days, 3 weeks, and 3 months). To do so, the gels are monitored via penetrometry, microscopy, and calorimetry. Although the gels do not show any significant difference during storage in the micrographs, the calorimetric and firmness data reveal meaningful results. The heat of dissolution increases in every system investigated, indicating post-crystallization processes. Due to different solubilities of wax components, the critical gelling concentration is determined and the solid wax content is retrieved to further address the structure efficiency (S.E.). It is demonstrated that although the quantity of solids over time increases, the scaffolding effectiveness decreases in most cases. Only SFW, most likely due to sintering, shows an increase in S.E. over the storage time. Identified synergistic effects in BW and hydrolyzate mixtures decrease with increasing storage time. This work aims to contribute to a better understanding of the behavior of wax-based oleogels upon storage. Practical Applications: Although much is known about the gel properties of wax-based oleogels at short-term, the behavior over the storage period remains largely unresolved. However, this behavior is immensely important for a real application in fast and slow moving consumer goods. After all, products should always have the same consumer-relevant properties when stored at variable time frames. This applies to both food and pharmaceutical products. Knowledge of the behavior of wax-based oleogels in terms of a time-dependent change can help to choose a targeted product design and ensure product quality and consumer satisfaction.