Reducing contaminants in vegetable oil

The chemical substances glycidol, 2-MCPD and 3-MCPD are produced when vegetable oil is processed. Excessive concentrations of these substances can be harmful to health. Wageningen University & Research is therefore working on ways to minimise the formation of these contaminants.

Chemical reaction during heating

During the refining of crude palm oil and other vegetable oils (for example from olives, coconuts and sunflower seeds), glycidol, 2-MCPD and 3-MCPD can be formed by a chemical reaction during heating. Heating of the oil is necessary to obtain the right colour, smell, taste and shelf life and to remove, among other things, pesticides and certain hydrocarbons. But heating also has disadvantages.

The toxicity of glycidol, 2- and 3-MCPD has been extensively investigated by the European Food Safety Authority (EFSA). The conclusions were the following:

  • Glycidol has mutagenic properties. Given the fact that children are especially at risk of consuming hazardous amounts, the European Commission (EC) decided to set maximum limits.
  • For the general population, the consumption of 3-MCPD is most likely not a risk. For children, the risk is greater, especially for children and babies who are exclusively fed with infant formula (milk powder).
  • For 2-MCPD, the EFSA has too little information available to draw a conclusion about its safety.

REFINE: limiting the formation of contaminants

In 2017, RIKILT started the four-year REFINE project. This is a public-private partnership between RIKILT and three companies: Special Refining Company BV, Spack BV and Care Naturkost GmbH & Co KG. The project focuses on reducing the formation of glycidol, 2- and 3-MCPD during the refining process and during trading and processing of organic oils and fats. The project is funded in part by the Dutch Ministry of Agriculture, Nature and Food Quality.

As part of the REFINE project, the industrial refining process was simulated on a pilot-plant scale at Special Refining Company BV. This has enabled researchers to measure the formation of the three contaminants during the process and test the effects of measures to reduce them (such as combinations of degumming, bleaching and deodorisation). The final goal of the project is to develop strategies that limit the formation of glycidol and 2- and 3-MCPD during the refining of vegetable oils.