Mitigation methods during physical refining for the reduction of 2- and 3-MCPD esters and glycidyl esters in (organic) high oleic sunflower and rapeseed oils

Summary

2-monochloropropane-1,3-diol esters (2-MCPDE), 3-monochloropropane-1,2-diol esters (3-MCPDE), and glycidyl fatty acid esters (GE) are process contaminants formed during the production of refined edible oils and fats. The aim of this research was to develop mitigation strategies for the formation of these contaminants in organic oils, mainly high oleic (HO) sunflower and rapeseed oil, during physical refining. Different strategies such as a double refining with a high-low deodorization temperature, water washing and increasing amounts of bleaching earth were compared with a single physical refining (control treatment). Experiments were conducted in a pilot-plant refinery. Compared with the control treatment, double refining successfully reduced the concentration of formed of GE in HO sunflower and rapeseed oil, respectively by, 70% and 94%. In particular, the second degumming and bleaching were crucial for eliminating GE concentrations. Both 2- and 3-MCPDE were formed during temperature ramping, prior to the deodorization process and the concentrations of these contaminants remained stable throughout the refining process. Doubling the amount of bleaching earth led to an approximately 48% decrease of 2- and 3-MCPDE levels in final HO sunflower oil. No decrease was observed in rapeseed oil. The results of our studies provide useful insights which can directly be implemented by the (organic) vegetable oil industry.