Glossary

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Refining

Processing and purification of raw materials such as crude vegetable oils

Plant oils often need refining to remove unwanted impurities. Refining typically destroys proteins and DNA making it virtually impossible to detect any difference between oils made from GM and conventional seeds.

Refining typically involves several stages:

• Degumming: Removes crude lecithin and fibrils (three percent of the crude oil).
• Neutralisation: Oils contain 0.3 to 6 percent fatty acids. These are removed to improve taste and extend shelf life.
• Bleaching: Removes pigments and soap residues
• Deodorisation: Removes residual compounds responsible for off-tastes and odours

At each step, the oil is heated to 220°C. Depending on the specific process, the oil may be treated with high pressure, steam, or chemicals.