Synchronous Fluorescence Spectroscopy of Edible Vegetable Oils. Quantification of Tocopherols

The study demonstrates the application of front face and right angle synchronous fluorescence spectroscopy for the characterization of edible oils. The method enables monitoring of tocopherols, pheophytins, and other fluorescent components in edible oils. Principal component analysis of synchronous fluorescence spectra revealed sample clustering according to the type of oil. Partial least-squares regression was utilized to develop calibration models between fluorescence spectra and total tocopherol content determined by HPLC. The regression models showed a good ability to predict tocopherol content. The best fitting results were obtained for 1% v/v diluted oils and for bulk samples using the entire spectrum, yielding the regression coefficient, r, of 0.991, and root mean square error of cross-validation of 8%. The results presented confirm the capabilities of the fluorescence techniques as a tool for the analysis of edible oils.

Keywords: Tocopherols; pheophytins; vegetable oils; synchronous fluorescence spectroscopy