Hexane in veggie burgers...
Posted by politicalmonty on Apr 14, 2010 · Member since Nov 2009 · 3633 posts
Has anyone else heard about hexane being put into veggie burgers? From the reports I've read, it's not good for you but it's been put into veggie burgers by - Amy's Kitchen, Garden Burger, Boca, Morningstar and many others. While I don't eat a lot of them anymore, I'm still concerned about the future meals of which I may partake.
Never heard of it, or what it supposedly does to your body, but if you rarely eat it, I wouldn't worry about the effects it will have. Now, if you enjoyed these burgers regularly, that could be a different story.
Part of the process of getting "isolated soy protein" from whole soy involves hexane, which is this: http://en.wikipedia.org/wiki/Hexane
basically first they remove the oil from the soybean, leaving defatted soy flour. Then (wiki):
"Edible soy protein "isolate" is derived from defatted soy flour with a high solubility in water (high NSI). The aqueous extraction is carried out at a pH below 9. The extract is clarified to remove the insoluble material and the "supernatant" is acidified to a pH range of 4-5. The precipitated protein-curd is collected and separated from the whey by centrifuge. The curd is usually neutralized with alkali to form the sodium proteinate salt before drying
Soy protein concentrate is produced by immobilizing the soy globulin proteins while allowing the soluble carbohydrates, soy whey proteins, and salts to be leached from the defatted flakes or flour. The protein is retained by one or more of several treatments: leaching with 20-80% aqueous alcohol/solvent, leaching with aqueous acids in the isoelectric zone of minimum protein solubility, pH 4-5; leaching with chilled water (which may involve calcium or magnesium cations), and leaching with hot water of heat-treated defatted soy meal/flour.
All of these processes result in a product that is 70% protein, 20% carbohydrates (2.7 to 5% crude fiber), 6% ash and about 1% oil, but the solubility may differ. One tonne of defatted soybean flakes will yield about 750 kg of soybean protein concentrate."
Yeah so anyway, hexane should be long gone by the end of this process. Hexane is also used to get oils out of other plants (canola, corn, etc), so as far as a potential contaminant, it could potentially be in those. In fact, that's more likely because hexane is a nonpolar solvent, meaning it can mix with these oils but not so much with polar components (water, amino acids, etc).
There are some websites that say there has been hexane contamination of soy flour/soy protein. With proper preparation, there really shouldn't be any. It's not an acute toxicant, it's more about chronic exposure.
Yeah, and from my experience working in a chemistry lab, I can tell you that hexane is very volatile, so when you heat the food, any that's left should be long gone, and the tiny bit that remains probably won't hurt you unless you're downing like, ten burgers a day.