Rapid Authentication of Olive Oil Adulteration by Raman Spectrometry

Abstract

The authentication of olive oil and its adulteration with lower priced oils are still serious problems in the olive oil industry. In this study, a method based on the intensity ratio of the Raman spectroscopy vibration bands, especially on the intensity ratio of the cis ( ==C-H) and cis (C=C) bonds normalized by the band at 1441 cm(-1) (CH(2)), was established to authenticate genuine/fake olive oil. These intensity ratios of the vibration bands given in the form of a two-dimensional chart allow first the discrimination between the various grades of olive oil and the seed oils and then the detection of olive oil fraud by the line of y = 0.7, which is observed under most experiments and dot charts. This method can reliably distinguish the genuine olive oils from the olive oils containing 5% (volume percentage) or more of other edible oils, such as soybean oil, rapeseed oil, sunflower seed oil, or corn oil. Compared to the traditional principal component analysis method, this method is more intuitive, more precise, and easier to use. Moreover, this method also has the advantages of simplicity efficiency and has no need for sample preprocessing, being especially suitable for on-site testing in field applications.

Color and Chemical Properties of Oil Used for Deep Frying on a Large Scale

“…European countries, such as Germany, France, Italy, Austria, Switzerland, Belgium, Spain, Portugal, Hungary, and Finland, employ PC for the determination of deteriorated oil below 25 or 27 3 , while one group 4, 5 claims that triacylglycerol oligomer content better describes the deterioration of oil and fat than PC does. In addition, methods for the determination of oil and fat deterioration such as gel-permeation liquid chromatography 6 , Fourier transform infrared spectroscopy 7 , laser desorption ionization time-of fl ight mass spectrometry 8 , Raman spectrometry 9 , fluorescence spectroscopy 10, 11 and matrix-assisted laser desorption/ionization time-of-fl ight mass spectrometry 12 are also proposed.…”

Composition and authentication of virgin olive oil from French PDO regions by chemometric treatment of Raman spectra

“…[15] However, two recent studies on the detection of the adulteration of VOOs have demonstrated the potential capabilities of CRS with 514.5 nm laser excitation [16] and of a portable Raman spectrometer equipped with a diode laser (785 nm). [17] Thus, FTRS has been used to determine the free fatty acids in olive fruits and olive oils, [18,19] total unsaturation in vegetable oils [20] and the water and oil contents in olive fruits and pomace [21,22] as well as to monitor the oxidation of edible oils. [23,24] However, the main applications are the authentication of the VOO and the detection of its adulteration by various edible oils: coconut, corn, garlic, grape seed, hazelnut, mustard, palm, peanut, rapeseed, safflower, sesame, sunflower, soybean, sweet almond and walnut.…”

Comparative Study of the Lipid Profiles of Oils from Kernels of Peanut, Babassu, Coconut, Castor and Grape by GC-FID and Raman Spectroscopy

“…23,24 However, in the last decade vibrational spectroscopies have been presented as an alternative, since the analysis is fast and usually the sample preparation is very simple. [25][26][27][28][29] Raman spectroscopy is an outstanding technique in the characterization of materials because allows obtaining finger print spectra with narrow and well resolved bands and water does not generate significant interference in the signal. This technique has been used in certification, authentication, search for adulteration of products, fatty acids determinations and in the analysis of the oxidation of oils.…”