Detection of Virgin Olive Oil Adulteration by Fourier Transform Raman Spectroscopy

Abstract

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. Keywords: Olive oil; adulteration; FT-raman spectroscopy; chemometrics; authentication

Spectroscopy: Developments in instrumentation and analysis

“…Thus, the authentication of agro-food products has become a crucial issue over the past decade (Simpkins and Harrison 1985;Dennis and Ashurst 1996). Authentication is usually defined as the assessment of a product to ensure that it conforms strictly with the description provided by its label and complies with the legislation in force in the country in which it is marketed or sold (Martin 1996;Aparicio et al 1996;Lees 1998;Aparicio 2000). Authentication is of paramount importance both for official bodies in charge of the control of labelling and for the industry where incoming batches of raw materials and finished products must be tested for compliance with specifications.…”

“…These strategies are complementary and need to be investigated when a study is done on the potential of a spectroscopic technique (Aparicio and Baeten 1998). One example is the successful attempt to calibrate the Raman or MIR spectrometers for the measurement of trilinolein (LLL) in virgin olive (Baeten et al 1996;Aparicio and Baeten 1998). In this study, virgin olive oil spiked with LLL was used to calibrate the spectrometer.…”

Chemometric Analysis of Croatian Extra Virgin Olive Oils from Central Dalmatia Region

“…Recent studies have also employed Fourier transform Raman spectroscopy (FT-Raman) for characterization of edible oils. [47][48][49][50] Some authors assume that for classification of oils and detecting adulteration, infrared spectroscopy is a better technique than Raman spectroscopy, 51 mainly due to the fact that the important bands for classification are of low intensity in Raman spectra. Opposite studies also exist.…”

Determination of Food Quality by Using Spectroscopic Methods

“…peroxide value) were obtained in a rapid, non-destructive and direct way [60]. FT-Raman spectroscopy combined with multivariate analysis procedures was applied to determine the level of adulteration of virgin olive oil by some vegetable oils (soybean, corn and raw olive residue oils) [61].…”