Acyl migration and hydrolysis in monoolein-based systems

The extent of acyl migration and hydrolysis phenomena in glycerol monooleate/water based systems and how they are affected by acetic acid and oleic acid has been examined. To facilitate analysis and interpretation of the data, samples with a low water content, 2–5 wt%, which form a liquid reverse micellar, L₂, phase, were chosen. Acyl migration and hydrolysis were monitored versus time by 13C NMR analysis. In addition, the acid value to monitor hydrolysis has been also determined. The formation of small amounts of glycerol-2-monooleate as well as hydrolysis products was observed. These phenomena depend on the water content and storage conditions. The implications of these findings for the observed phase behaviour of the glycerol monooleate/water system are discussed.