FTIR spectroscopy coupled with chemometrics of multivariate calibration and discriminant analysis for authentication of extra virgin olive oil

The objective of this study was to develop FTIR spectroscopy combined with chemometrics for the authentication of extra virgin olive oil (EVOO) from grape seed oil (GSO), soybean oil (SO), and walnut oil (WO). FTIR spectra of EVOO and that mixed with GSO, SO, and WO were scanned at mid infrared region (4000–650 cm−1). The optimized wavenumbers region was used for the quantification of oil adulterants using multivariate calibration of partial least square (PLS) and principle component regression (PCR) as well as for classification using discriminant analysis (DA). PLS at optimized wavenumbers was used with R2 for the relationship between actual and predicted values of GSO, SO, and WO was >0.99. The values of root mean square error of calibration (RMSEC) were relatively low, i.e. 0.308%, 0.658%, and 0.101% for GSO, SO, and WO, respectively. DA at the optimized frequency region could successfully classify EVOO and EVOO adulterated with GSO, SO, and WO.