COMPARISON OF THE COMPOSITION AND PROPERTIES OF CANOLA AND SUNFLOWER OIL SEDIMENTS WITH CANOLA SEED HULL LIPIDS

The phase transition behavior and chemical composition of sediments fr om Canadian and Australian canola oils, as well as from sunflower oil, were studied by differential scanning calorimetry, X-ray diffraction, polarized-light microscopy, and chromatographic techniques. Australia n canola sediment was similar to Canadian canola sediment in both melt ing and crystallization behaviors and chemical composition. Compared t o canola sediment, sunflower sediment underwent phase transformation ( melting and crystallization) at lower temperatures, and the enthalpies associated with the phase changes were greater. The X-ray diffraction patterns for these materials were similar, indicating identical cryst alline structures. Sunflower sediment contained mainly wax esters (99% ), while canola sediment contained about 72-74% of waxes. Moreover, su nflower sediment consisted of shorter-chainlength fatty acids and alco hols than canola sediment. A hexane-insoluble fraction from Canadian c anola hull lipids had fatty acid and alcohol profiles and X-ray diffra ction pattern similar to the corresponding oil sediment.