NIR and MIR Infrared: The Spectroscopic technique for the traceability and authentication of olive oils and wines

 Irene Gouvinhas,1 Ana Novo Barros1

1Centre for the Research and Technology of Agro-Environmental and Biological Sciences, CITAB, UTAD, Vila Real, Portugal,

Some spectroscopical techniques have been extensively explored for the assessment of contents of various food matrices. Among these, vibrational techniques, such as IR, generally Fourier Transform-IR (FTIR), and Raman, have emerged recently as analytical methods widely used for food and feed analysis [1].

Actually, the conventional measurements employed in the assessment of the chemical composition of foods, such as peroxide values, fatty acids, phenolic and volatile compounds, are time consuming and require large amounts of reagents and solvents, which are toxic and expensive. Furthermore, they require the pre-treatment of sample. On the other hand, spectroscopical means, such as FTIR—particularly when used in conjunction with Attenuated Total Reflectance (ATR), dismiss any kind of sample preparation, avoiding the occurrence of chemical transformations, such as oxidation [2,3]. Furthermore, while the ATR module works within the medium-IR range (MIR), there are other accessories available, such as Diffuse Reflectance Integrating Sphere-FT (DRIFT), which, besides also dismissing the sample preparation, register the samples’ spectrum within the near-IR (NIR) range, thus retrieving supplementary information [4].

These vibrational spectroscopic methods provide information about the chemical composition of various food and biological materials, and molecular structure. In the last few years, our research group is focused in the implementation of IR spectroscopy, coupled to chemometric data analysis methods, for the authentication and traceability of olive oils and wines, supplying the use of classical methodologies, and in some cases, without even the destruction or opening the bottles.


  1. Li-Chan, E.C.Y.; Griffiths, P.R.; Chalmers, J.M. Applications of vibrational pectroscopy in food science. In Analysis of Food, Drink and Related Materials; John Wiley and Sons: Chichester, UK, 2010; Volume
  2. Gouvinhas, I.; Almeida, J.M.M.M.; Carvalho, T.; Machado, N.; Barros, A.I.R.N.A. Discrimination and characterization of extra virgin olive oils from three cultivars in different maturation stages using Fourier transform infrared spectroscopy in tandem with chemometrics. Food Chem. 2015, 174, 226–232.
  3. Gouvinhas, I.; Machado, N.; Carvalho, T.; Almeida, J.M.M.M.; Barros, A.I.R.N.A. Short wavelength Raman spectroscopy applied to the discrimination and characterization of three cultivars of extra virgin olive oils in different maturation stages. Talanta 2015, 132, 829–835.
  4. Wang, P.; Sun, J.; Zhang, T.; Liu, W. Vibrational spectroscopic approaches for the quality evaluation and authentication of virgin olive oil. Appl. Spectr. Rev. 2016, 51, 763–790.


This work was funded by national funds from by FCT – Portuguese Foundation for Science and Technology, under the projects UIDB/04033/2020 and POCI-01-0145-FEDER-006958.