Comparison of fatty acid profiles and mid‐infrared spectral data for classification of olive oils

Abstract

The composition of olive oils may vary depending on environmental and technological factors. Fatty acid profiles and Fourier‐transform infrared (FT‐IR) spectroscopy data in combination with chemometric methods were used to classify extra‐virgin olive oils according to geographical origin and harvest year. Oils were obtained from 30 different areas of northern and southern parts of the Aegean Region of Turkey for two consecutive harvest years. Fatty acid composition data analyzed with principal component analysis was more successful in distinguishing northern olive oil samples from southern samples compared to spectral data. Both methods have the ability to differentiate olive oil samples with respect to harvest year. Partial least squares (PLS) analysis was also applied to detect a correlation between fatty acid profile and spectral data. Correlation coefficients (R2) of a calibration set for stearic, oleic, linoleic, arachidic and linolenic acids were determined as 0.83, 0.97, 0.97, 0.83 and 0.69, respectively. Fatty acid profiles were very effective in classification of oils with respect to geographic origin and harvest year. On the other hand, FT‐IR spectra in combination with PLS could be a useful and rapid tool for the determination of some of the fatty acids of olive oils.

Prediction of various chemical parameters of olive oils with Fourier transform infrared spectroscopy

“…As indicated in this study and also in the literature components having high concentrations could be predicted well from FTIR spectra. These findings are also supported by the work of Gurdeniz, Ozen, and Tokatli (2010) in which stearic, oleic and linoleic acids were predicted quite well as in the present case. It was also reported successful predictions of stearic, arachidic and linolenic acids in the same study.…”

Effects of malaxation temperature and harvest time on the chemical characteristics of olive oils

“…Palmitic acid (C16:0) responsible for over 90% of saturated fatty acid composition of olive oil, ranged between 11.50 and 14.87%. Ayvalik oils had significantly higher saturated fatty acids than Memecik olive oils, similar to the previous observations (Gurdeniz, Ozen, & Tokatli, 2010). As reported by Manai-Djebali et al (2012), olive oils of high SFA contents are expected to be less prone to oxidation than those high in PUFA.…”

A Simple and Portable Screening Method for Adulterated Olive Oils Using the Hand‐Held FTIR Spectrometer and Chemometrics Tools

“…An oil sample can be measured directly and quickly, then much information about the sample can be extracted from the spectrum by manual interpretation or chemometrics tools. Therefore, FTIR spectroscopy has been widely utilized for the quality assessments of edible oils, including the authentication (Gurdeniz, Ozen, & Tokatli, 2010;Javidnia, Parish, Karimi, & Hemmateenejad, 2013), the adulteration screening (Oussama, Elabadi, Platikanov, Kzaiber, & Tauler, 2012;Sun, Lin, Li, Shen, & Luo, 2015), and the determination of free fatty acids (Li, Garcia-Gonzalez, Yu, & van de Voort, 2008;Mahesar, Sherazi, Khaskheli, Kandhro, & Uddin, 2014), trans fatty acids (Mossoba, Milosevic, Milosevic, Kramer, & Azizian, 2007;Sherazi et al, 2009; Tyburczy, Mossoba, & Rader, 2013), peroxide values (Allendorf, Subramanian, & Rodriguez-Saona, 2012;Aykas & Rodriguez-Saona, 2016), cloud points (Setiowaty & Man, 2004), and other physical and chemical parameters (Luna, da Silva, Ferre, & Boque, 2013;Nunes, 2014).…”