PhotooxidationEffect in Liquid Lipid Matrices: Answers from an Innovative FTIR Spectroscopy Strategy with "Mesh Cell" Incubation.

Developing new approaches to evaluate the stability of edible oils under moderate conditions is highly demanded today to avoid accelerated experiments that are not well correlated with actual shelf life. In particular, low intensity of visible light (photooxidation) needs to be integrated in stability studies, together with mild temperature. Thus, in this work, a strategy based on a "mesh cell"-FTIR to monitor chemical changes in lipid matrices using a combination of light and mild heating was applied. The results were compared with those obtained for the stability of triolein used as a molecular model. The study showed that the moderate light intensity (400 lx) at a low temperature (23 °C) has an early effect on the degradation of lipid matrices that is not observed when they are stored at 35 °C in the absence of light. Thus, the results proved that the exposure to light (400 lx) was more relevant than mild heating (35 °C) in monounsaturated lipid matrices, while polyunsaturated lipid matrices were more sensitive to mild heating.