Structure and Physical Properties of Organogels Developed by Sitosterol and Lecithin with Sunflower Oil

High linoleic acid sunflower oil ( HLSO ) with various sitosterol ( Sit ) to lecithin ( Lec ) mass ratios (i.e., 0:100–100:0) were used to develop organogels at two storage temperatures ( T s : 5 and 25 °C). The results showed that, at 25 °C, the hardness value of organogels obtained from HLSO with both Sit and Lec was higher than that of organogels developed from HLSO with only Sit or Lec . Microscopy revealed that the shapes of the crystals in the organogels varied significantly with the composition of the structurant and the T s . At both T s used, the Sit:Lec (80:20) system had a lower degree of supersaturation compared with the (100:0) system. X-ray diffraction (XRD) revealed that Sit:Lec mass ratio of 70:30, 80:20 and 100:0 had similar short spacings, and the presence of Lec might be adverse to the formation of Sit crystal in oil. Small-angel X-ray scattering (SAXS) showed that the layer thickness of Sit/Lec/HLSO organogel was larger than that of Sit/HLSO organogel. It was found that the presence of Lec induced the change of self-assembly structure of Sit in HLSO and caused the changes of physical properties of organogels obtained.