Structure and thermal properties of beeswax-based oleogels with different types of vegetable oil

M Pang,Z Lei,Z Shi,L Cao,S Jiang,Y Ge

doi:10.3989/gya.0806192

Abstract

Beeswax-based oleogels with different types of vegetable oil, including camellia oil (CO), soybean oil (SO), sunflower oil (SFO), or flaxseed oil (FO), were prepared and their structure and thermal properties were evaluated. The critical concentration of oleogel obtained from each of CO, SO, and SFO at 25 °C was 3% (w/w), and that from FO was 4%. Thermal measurements revealed similar thermodynamic curves for oleogels in different lipid phases. X-Ray diffraction showed orthorhombic perpendicular subcell packing and characteristic peaks of the β’ form. Furthermore, a morphology analysis of the crystals showed that they were needle shaped. Fourier transform-infrared spectra revealed that beeswax-based oleogels were formed via non-covalent bonds and may be stabilized with physical entanglements. The oleogels showed oil type-dependent oxidative abilities, but they were all stable and showed no obvious changes in peroxide value during 90 days of storage at 5 °C.

Highlights

To gain a better understanding of the differences in critical concentrations required for oleogel formation from the different oils, the composition of fatty acid in these four oils was measured
The critical concentration, thermal properties, structural characteristics, and oxidative stability of beeswax-based oleogels were investigated in this study
It was visually observed that the beeswaxbased oleogels had a smooth and uniform surface, and the results of X-Ray diffraction (XRD) and Polarized Light Microscopy (PLM) confirmed that it had an orthorhombic perpendicular (O⊥) subcell structure and long needle-like crystals, so that the formation of microstructures were independent of the oil phase