High field 1H and 13C NMR has been used to identify the region where an olive oil was produced – See Segre et al. Other methodologies have involved reacting hydroxyl groups in the olive oil with phospochloridite which allows detailed 31P NMR signatures to be obtained that reveal detailed chemistry distributions within the olive oil allowing an even greater discernment of chemical differences based on origin.
Much of the work in this area has been performed by Apostolos Spyros in Crete. Here are a few of his papers:
“Application of 31P-NMR spectroscopy in food analysis. I. Quantitative determination of mono- and diglycerides in virgin olive oils”. A. Spyros, Photis Dais, J. Agric. Food Chem., 2000, 48, 802 . (pdf)
“Quantitative determination of the distribution of free hydroxylic and carboxylic groups in unsaturated polyester and alkyd resins by 31P NMR spectroscopy”.A. Spyros, J. Appl. Polym. Sci., 2002, 83, 1635. (pdf)
“Kinetics of diglyceride formation and isomerization in virgin olive oils by employing 31P NMR spectroscopy. Formulation of a quantitative measure to assess olive oil storage history”. A. Spyros, A. Fillipidis and P. Dais, J. Agric. Food Chem., 2004, 52, 157. (pdf)
This approach has also been applied to other edible oils so that their presence as adulterants can be observed and quantified:
“Classification of edible oils by employing 31P and 1H NMR Spectroscopy in combination with multivariate statistical analysis. A proposal for the detection of seed oil adulteration in virgin olive oils “. G. Vigli, A. Fillipidis, A. Spyros and P. Dais, J. Agric. Food Chem., 2003, 51, 5715. (pdf)
“Detection of extra virgin olive oil adulteration with lampante olive oil and refined olive oil using NMR spectroscopy and multivariate statistical analysis”. G. Fragaki, A. Spyros, G. Siragakis, E. Salivaras, P. Dais, J. Agric. Food. Chem., 2005, 53, 2810.(pdf)
Please contact Process NMR Associates with your potential 31P analysis.
