Reducing saturated fat in foods is an increasingly important health objective due to its impact on population health and global sustainability. Fat is a highly functional component of food products; impacting spreadability, texture, and shelf life. The fatty acid composition of saturated fat contributes to its crystallisation and solid fat content, influencing how the fat behaves in food, determining which products are most suitable. Oleogels are a recently emerged alternative, proven to mimic some functionalities of fats, where a gelator (such as wax) restricts oil mobility, acting as the solid component creating a three-dimensional network trapping the liquid oil. Although the incorporation of oleogels in foods is promising, there is a great need to address the challenges with oleogel’s composition and consumer acceptability, due its gel-like structure.
This work aims to understand the effects of partially replacing palm oil (PO) with sunflower oil (SFO) and rice bran wax (RBW) to reduce the amount of saturated fat in bakery products, whilst maintaining their physicochemical properties. Various fat blends, consisting of 75% PO, 25% SFO, and RBW additions (1%, 2%, 3%, 5%) were analysed using polarised light microscopy, differential scanning calorimetry (DSC), oscillatory rheology and x-ray diffraction (XRD).
The results suggest that RBW provides nucleation sites for PO due to its fast crystallisation and causes the PO to crystallise at a lower temperature, shown in DSC. In addition, higher concentrations of RBW appeared to structure the liquid component of the blends, increasing the firmness and creating PO-based oleogels. These findings were supported by the rheology results, where RBW increased the elastic component of the blends (osscilation yield stress: 0% RBW – 0.00316%, 5% RBW – 0.0685%). XRD confirmed that α, β′ and β crystal polymorphs were present, showing potential in bakery products. These findings show that the synergistic interaction between RBW and PO can improve the physicochemical properties of the blends. This gives the potential to reduce saturated fat whilst maintaining important structural properties in bakery applications.