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

Delta(5)-Avenasterol, an ethylidene side-chain phytosterol, was described as an anti-polymerisation 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 degrees 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 alpha-tocopherol, showed that this tocol inhibited the polymerisation of the oil while fucosterol did not. (C) 1999 Society of Chemical Industry.