Thermal degradation of glycidyl esters in monoglycerides and mono- and diglyceride blends

As side products of concern, glycidyl fatty acid esters (GE) are an unwanted impurity in food emulsifier production. This study investigates the reduction of the GE content in such monoglycerides and their blends with diglycerides (mono-/diglycerides) by thermal post-treatment. The results indicate that the kinetics of GE reduction and equilibrium concentrations largely depend on the specific temperatures applied. For instance, while reaching equilibrium levels of GE can take several weeks at 80°C, they can be reached within hours at 150°C. The thermal treatment can have, however, also negative impact on other quality parameters, like the content of monoglycerides in both, distilled monoglycerides and mono-/diglycerides. Based on 47 laboratory and pilot trials the influence of post-treatment temperatures between 80 and 200°C on reducing GE levels has been systematically investigated. The obtained data were analyzed by mathematical modeling.