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 A degrees C). The results showed that, at 25 A degrees 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.