Effects of heating, aerial exposure and illumination on stability of fucoxanthin in canola oil

The effects of heating, aerial exposure and illumination on the stability of fucoxanthin was investigated in canola oil. In the absence of air and light, the heating caused the degradation of total and all-trans fucoxanthin at all tested temperatures between 25 and 100 °C. The increase of heating temperature promoted the formation of 13-cis and 13′-cis and the degradation of 9′-cis. The degradation and formation reactions were found to follow simple first-order kinetics and to be energetically unfavorable, non-spontaneous processes. Arrhenius-type temperature dependence was observed for the degradation of total and all-trans fucoxanthin but not for the reactions of cis isomers. The aerial exposure promoted the oxidative fucoxanthin degradation at 25 °C, whilst illumination caused the initial formation of all-trans, with concurrent sudden degradation of 13-cis and 13′-cis, and the considerable formation of 9′-cis. The fucoxanthin degradation was synergistically promoted when exposed to both air and light.