Investigation of the phase behavior ofCruciferae seed oils by temperature programmed X-ray diffraction

Abstract

The phase behavior of the seed oils from different strains ofBrassica napus, Brassica campestris, Sinapis alba, Crambe abyssinica andErysimum orientale is reported. The rapeseed oils and white mustardseed oils include products from plant breeding work in Canada and Sweden. The experimental technique includes the continuous recording of X-ray diffraction patterns vs. temperatures between −50 C and complete melting of the most stable solid phases with a new DPT (Diffraction-Pattern-Temperature) camera. The crystallization and melting of oils with an erucic acid content above 8% can be described in terms of the polymorphic phases α, β₂ and β₁ (in the order of increasing stability). The designation β₂ is tentative as the phase cannot be classified unambiguously by X-ray diffraction data alone. The phase transition temperatures for a certain species form continuous functions of the erucic acid content, thus providing a basis for the prediction of some of the properties that are relevant for the utilization of the oils in the food industry.