Evaluating the oxidative stability of triacylglycerols in rapeseed (Brassica napus) oleosomes

Abstract

Unsaturated triacylglycerols (TAGs) are stored in natural droplets called oleosomes in seeds. The storage in oleosomes was suggested to increase TAGs' oxidative stability. In this study, we tested the oxidative stability of TAGs in rapeseed oleosomes and compared it with the one of TAGs stored as bulk oils or incorporated into oil‐in‐water emulsions stabilized by rapeseed lecithin. Oleosome oil‐in‐water emulsions (Фoil = 0.1) were created and stored along with the bulk oils and lecithin emulsions for 63 days at 40°C. The TAGs in oleosomes were more oxidatively stable than in the bulk oils and lecithin emulsions, as indicated by the 17‐day longer lag phase and a 1.6–1.8 times slower maximal hydroperoxide formation compared to the bulk oils and lecithin emulsions. Moreover, we made the first steps towards understanding the high stability of TAGs in oleosomes by monitoring the consumption of oleosome‐associated antioxidants (tocopherols and carotenoids). Using oleosome extracts could be a strategy to retard TAGs oxidation in oil‐in‐water emulsions.