Do monoacylglycerols act as pro-oxidants in purified soybean oil? Evidence of a dose-dependent effect

An investigation was carried out on the effect of adding increasing amounts of monoacylglycerols (MAG) - obtained from a purified soybean oil (PSO) - on the oxidation of the same PSO. PSO and the MAG/PSO solutions were subjected, during accelerated oxidation at 60°C, to routine analyses and High-Performance Size-Exclusion Chromatography of polar compounds. The addition of low amounts of MAG (5-10 g kg -1) caused an increase of oxidation. Adding higher amounts of MAG, the pro-oxidant effect progressively decreased. The solution containing 30 mg kg -1 showed the lowest oxidative levels. Therefore, the effect of MAG in PSO oxidation is not univocal, being dose-dependent