Independent components analysis applied to 3D-front-face fluorescence spectra of edible oils to study the antioxidant effect of Nigella sativa L. extract on the thermal stability of heated oils

Independent Components Analysis (ICA) is one of the most widely used methods for blind source separation. In this paper we use this technique to facilitate the analysis of 3D- front face fluorescence spectra and to evaluate the efficiency of Nigella seed extract as a natural antioxidant compared with butylated hydroxytoluene (BHT) during accelerated oxidation of edible vegetable oils at 120 degrees C, 140 degrees C, 170 degrees C and 190 degrees C. ICA has demonstrated its power to extract the most informative signals and thus to allow the interpretation of the differences observed in the corresponding IC scores between Control, BHT-spiked and Nigella-spiked samples. The results of the study clearly indicate that the natural seed extract at a level of 800 ppm exhibited antioxidant effects similar to those of the synthetic antioxidant BHT at a level of 200 ppm and thus contributes to an increase in the oxidative stability of the oil. (c) 2011 Elsevier B.V. All rights reserved.