A new application of X-ray scattering using principal component analysis - classification of vegetable oils

Vegetable oils from corn, canola, soybean, sunflower and olive (extra virgin and others) were analysed and classifications were obtained using information from the scattered radiation. For the corn, canola, soybean and sunflower oil analyses, the PC1 × PC4 score plots show distinct groups for each oil. These differences related to the variable fatty acid contents in the samples. Considering the discrimination between extra virgin and other olive oils, the PC1 × PC2 scores plot shows two groups of samples. The main difference between them can be attributed to the total absence of water in extra virgin olive oils, since this first extraction is performed at room temperature without any kind of reagent. The technique is very useful to rapidly classify vegetable oil samples at very low cost, with the possibility of performing the measurements in situ with a portable instrument.