Determination of oxidation stability and degradation degree of rapeseed oil methyl ester by fluorescence spectroscopy

- The oxidation stability of the rapeseed oil methyl ester (RME) is related to the oxidation products and natural antioxidants.
- Quick and direct determination of the degradation degree and the oxidation stability of RME are enabled by fluorescence spectroscopy.

The degradation of rapeseed oil methyl ester (RME) under accelerated conditions was investigated by use of total fluorescence spectroscopy (TFS). This technique provides an easy and quick analysis of natural antioxidants (e.g. vitamin E, chlorophylls, etc.) and of oxidation products (e.g. hydroperoxides and oligomers) of RME at their characteristic excitation and emission wavelengths. In the result it was proven that similar to the specification related Rancimat-test (EN 14112) the oxidation stability of RME could be determined by fluorescence signals of the oxidation products. Additionally a quick and direct determination of the degradation degree and the oxidation stability of RME by fluorescence spectroscopy is enabled by use of the correlation between the Rancimat- and the fluorescence-measurement.