Extra virgin olive oil is the fundamental compound of the Mediterranean diet, because of its nutritional value. It is a natural juice, coming from the olive fruit through process. There are regulations internationally for the protection of the genuineness and quality of extra virgin olive oil.
Regulations involve test analysis and analytical procedures.
The spectroscopic/spectrometric method is another method used for the determination of the authenticity of olive oil.
The Nuclear Magnetic Resonance (NMR) technique has its advantages. It can detect simultaneously the low-mass components. It is used for determining the authenticity of extra virgin olive oil, based on the determination of the fatty acids and oleic and linoleic acids.
Here is an interesting article:
1H Nuclear Magnetic Resonance Study of Olive Oils Commercially Available as Italian Products in the United States of America
(This article belongs to the Special Issue Foodomics 2011)
Multivariate analysis of 1H NMR data has been used for the characterization of 12 blended olive oils commercially available in the U.S. as Italian products. Chemometric methods such as unsupervised Principal Component Analysis (PCA) allowed good discrimination and gave some affinity indications for the U.S. market olive oils compared to other single cultivars of extra virgin olive oil such as Coratina and Ogliarola from Apulia, one of Italy’s leading olive oil producers, Picual (Spain), Kalamata (Greece) and Sfax (Tunisia). The olive oils commercially available as Italian products in the U.S. market clustered into 3 groups. Among them only the first (7 samples) and the second group (2 samples) showed PCA ranges similar to European references. Two oils of the third group (3 samples) were more similar to Tunisian references. In conclusion, our study revealed that most EVOO (extra virgin olive oils) tested were closer to Greek (in particular) and Spanish olive oils than Apulia EVOO. The PCA loadings disclose the components responsible for the discrimination as unsaturated (oleic, linoleic, linolenic) and saturated fatty acids. All are of great importance because of their nutritional value and differential effects on the oxidative stability of oils. It is evident that this approach has the potential to reveal the origin of EVOO, although the results support the need for a larger database, including EVOO from other Italian regions.
Analysis by florescence spectroscopy is an extensively used research in vegetable oils including olive oil.
The florescence spectroscopy is important for its high sensitivity and its speedy analysis. This method has the ability to detect refined oil.
Mass spectrometry (MS) is an advanced method for the analysis of olive oils. In recent years electrospray ionization mass spectroscopy (ESI-MS) and Inductively Coupled Plasma (ICP-MS) -very advanced instruments- have been used for the evaluation of the quality of olive oil.
Small molecules and bio-macromolecules are analyzed by soft ionization MS methods. These methods have the ability to detect adulterants in olive oil.
The Raman spectroscopy is a technique that also has been used for the detection of adulterants in olive oils.
The Fournier transform Infra-red spectroscopy (FT-IR) has been used to detect the adulteration of virgin olive oil with vegetable oils and refined olive oils.
Methods based on DNA can provide information about the identity of olive oil cultivar, due to environmental effects.