A study on the influence of fucosterol on thermal polymerisation of purified high oleic sunflower triacylglycerols

Δ⁵-Avenasterol, an ethylidene side-chain phytosterol, was described as an antipolymerisation agent for thermooxidised oils. This paper investigates the potential of its commercially available geometrical isomer, fucosterol, as an antipolymerisation agent for high oleic sunflower oil (HOSO). Purified triacylglycerols were prepared from HOSO and incubated in an oven, at 180°C, with or without fucosterol, sitosterol and stigmasterol. Analysis of polymers and dimers (by high-performance size exclusion chromatography) showed that fucosterol did not affect the rate of polymerisation of purified HOSO triacylglycerols in our model. Comparison with α-tocopherol, showed that this tocol inhibited the polymerisation of the oil while fucosterol did not.