What is hexane?
Hexane is a colorless liquid hydrocarbon of the alkane series. It is a byproduct of gasoline refining. Processors use it as a solvent — a cheap and efficient way of extracting oils, a necessary step to making most conventional soy oil and protein ingredients. Whole soybeans are literally bathed in hexane to separate the soybeans’ oil from protein. Hexane is a neurotoxin, according to the Centers for Disease Control (CDC), and a “hazardous air pollutant,” according to the Environmental Protection Agency (EPA).
When used to extract palm oil, a byproduct known as 3-MCPD is formed. 3-MCPD is an organic chemical compound which is the most common member of chemical food contaminants known as chloropropanols. It is suspected to be carcinogenic in humans. This substance forms during food processing, in particular, when refining vegetable oils at high temperatures (approx. 200°C). The European Union banned the use of hexane to extract oils. Read a blog all about 3-MCPD here.
Hexane Residues in Food
The FDA does not set a maximum residue level in soy foods for hexane, and does not require that food manufacturers test for residues. The European Union, on the other hand, has adopted a directive setting maximum limits of solvent residues in foods, including hexane residues in soy ingredients. For defatted soy flour used as ingredients in consumer foods, the European Union prohibits levels of hexane residues greater than 10 ppm. When The Cornucopia Institute tested samples of soy ingredients for hexane residues, levels as high as 21 ppm were found.