Detection of virgin olive oil adulteration by Fourier transform Raman spectroscopy

The authenticity of products labeled as virgin olive oil is of great importance from commercial and health aspects. The combination of Fourier transform-Raman (FT-Raman) spectroscopy with multivariate procedures has been used for predicting the level of adulteration in a set of virgin olive oil samples that were adulterated with soybean, corn, and raw olive residue (olive pomace) oils at 1, 5, and 10%, respectively. Six genuine virgin olive oil samples, differing in their chemical composition, were selected from a set of 1428 European samples. The best result in prediction of adulteration was an adjusted R(2) value of 0.964, determined by regression on principal components (PCR), giving 100% correct discrimination between genuine and adulterated samples and 91.3% correct classifications at different adulteration levels.