The use of FTIR spectroscopy and chemometrics for rapid authentication of extra virgin olive oil

Abstract

The authenticity of high value edible fats and oils including extra virgin olive oil (EVOO) is an emerging issue, currently. The potential employment of Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics of multivariate calibration and discriminant analysis has been exploited for rapid authentication of EVOO from canola oil (Ca-O). The optimization of two calibration models of partial least square (PLS) and principle component regression was performed in order to quantify the level of Ca-O in EVOO. The chemometrics of discriminant analysis (DA) was used for making the classification between pure EVOO and EVOO adulterated with Ca-O. The individual oils and their blends were scanned on good contact with ZnSe crystals in horizontal attenuated total reflectance, as a sampling technique. The wavenumbers of 3,028-2,985 and 1,200-987 cm-1 were used for quantification and classification of EVOO adulterated with Ca-O. The results showed that PLS with normal FTIR spectra was well suited for quantitative analysis of Ca-O with a value of the coefficient of determination (R 2) > 0.99. The error, expressed as root mean square error of calibration obtained was relatively low, i.e. 0.108 % (v/v). DA can make the classification between pure EVOO and that adulterated with Ca-O with one misclassified reported.