Fluorescence Spectroscopy Based Characterization of Flaxseed Oil

Abstract

Fluorescence spectroscopy has been employed for the compositional analysis of axseed oil, detection of its adulteration and investigation of the thermal effects on its molecular composition. Excitation wavelengths from 320 to 420 nm have been used to explore the valued ingredients in axseed oil. The emission spectra of axseed oil revealed that it contains high concentration of vitamin K, isomers of vitamin E, carotenoids and chlorophylls with corresponding emission spectra at 390, 414, 441, 475, 515 and 673/720 nm, which can be used as a marker for quality analysis. Detection of adulteration of canola oil in axseed oil has been demonstrated by applying principal component analysis. Moreover, the effects of temperature on the molecular composition of cold pressed axseed oil has been explored by heating them at cooking temperatures of 100, 110, 120, 130, 140, 150, 160, 170 and 180°C, each for 30 minutes. On heating, the deterioration of vitamin E, carotenoids and chlorophylls occurred with an increase in the oxidation products. However, it was found that up to 140°C, axseed oil retains much of its natural composition whereas up to 180 o C, it loses much of its valuable ingredients along with increase of oxidized products.