Fluorescence of vegetable oils: olive oils.

Fluorescence spectra of undiluted extra virgin olive oil obtained with the traditional setup (right-angle fluorescence) show considerable artifacts and deformations due to self-absorption phenomena, even when the spectra are corrected for inner filter effects. On the other side, front-face fluorescence spectra are much less affected by self-absorption. Front-face fluorescence of native olive oil reveals the presence of different fluorophores and can provide information about their amount. From the intense emission at ca. 315-330 nm, it is possible to detect fluorescent polyphenols and pherols and to evaluate their overall content. Low-intensity emission bands at 350-600 nm are correlated to vitamins and other important molecules. Among them, the fluorescence of the riboflavin fluorophore can be used to evaluate its concentration. The intense emission of chlorophyll derivatives, measured in the 640-800 nm spectral region, can provide information on their concentration.

[1]  M. Tsimidou,et al.  Solid phase extraction: Applications to the chromatographic analysis of vegetable oils and fats , 2002 .

[2]  L. Carbonaro,et al.  Direct fluorometric determination of fluorescent substances in powders: the case of riboflavin in cereal flours. , 2003, Journal of agricultural and food chemistry.

[3]  Maurizio Servili,et al.  Simple and hydrolyzable phenolic compounds in virgin olive oil. 1. Their extraction, separation, and quantitative and semiquantitative evaluation by HPLC , 1992 .

[4]  Joseph R. Lakowicz,et al.  Instrumentation for Fluorescence Spectroscopy , 1983 .

[5]  G. Mellerio,et al.  Characterization of phenolic and secoiridoid aglycons present in virgin olive oil by gas chromatography-chemical ionization mass spectrometry , 1996 .

[6]  Teresa Galeano Díaz,et al.  Simultaneous fluorometric determination of chlorophylls a and B and pheophytins a and B in olive oil by partial least-squares calibration. , 2003, Journal of agricultural and food chemistry.

[7]  L. Moberg,et al.  Spectrofluorimetric determination of chlorophylls and pheopigments using parallel factor analysis. , 2001, Talanta.

[8]  B. Gandul-Rojas,et al.  Action of chlorophylls on the stability of virgin olive oil , 1992 .

[9]  F. Visioli,et al.  Olive Oil Phenols and Their Potential Effects on Human Health , 1998 .

[10]  F. Gutiérrez-Rosales,et al.  Main polyphenols in the bitter taste of virgin olive oil. Structural confirmation by on-line high-performance liquid chromatography electrospray ionization mass spectrometry. , 2003, Journal of agricultural and food chemistry.

[11]  Bo Karlberg,et al.  Validation of a multivariate calibration method for the determination of chlorophyll a, b and c and their corresponding pheopigments , 2001 .

[12]  N. Kyriakidis,et al.  Fluorescence spectra measurement of olive oil and other vegetable oils. , 2000, Journal of AOAC International.

[13]  M. Servili,et al.  Antioxidant activity of tocopherols and phenolic compounds of virgin olive oil , 1996 .

[14]  Stefania Vichi,et al.  Solid-phase microextraction in the analysis of virgin olive oil volatile fraction: characterization of virgin olive oils from two distinct geographical areas of northern Italy. , 2003, Journal of agricultural and food chemistry.

[15]  Carmen García,et al.  Development in lipid analysis: Some new extraction techniques and in situ transesterification , 2000, Lipids.

[16]  B. Gandul-Rojas,et al.  Color-pigment correlation in virgin olive oil , 1991 .

[17]  Xueli Cao,et al.  Supercritical fluid extraction of grape seed oil and subsequent separation of free fatty acids by high-speed counter-current chromatography. , 2003, Journal of chromatography. A.