The study published in the Journal of Agricultural and Food Chemistry reports a method for determining residual proteins in refined oils – a potential trigger of allergic reactions. The research team behind the new method then used it to test for proteins in commercial samples of fully refined oils, as well as in samples of oil from different points of the refining chain.
“On the basis of the analysis of residual protein in the highly refined oils presented in this paper, even the most sensitive individuals included in such studies would need to consume at least 50 g of highly refined oil to experience subjective symptoms,” wrote the researchers, led by Clare Mills of the Institute of Food Research, UK.
They added that the findings are consistent with observations in clinical studies that the allergenic activity of residual proteins in refined soybean oils is insufficient to elicit a reaction in oral challenge tests.
‘May contain’
David Reading of Food Allergy Support , UK, said that the study highlights “a vital point for the food industry to consider.”
“According to our advisers, no conceivable allergenic risks would occur from the use of shared equipment for products that contain refined oils. The amount of proteins that could conceivably be transferred to the next product manufactured with this shared equipment is extraordinarily low,” said Reading.
“It is our personal view, based on conversations with experts in the food industry, that where a refined oil is used in products that are made on shared equipment, a “may contain” label on other foods using the same equipment would not be necessary and indeed would be highly misleading,” he added.
However, Reading explained that food manufacturers must perform their own risk assessments and make individual judgements on such issues.
Allergy threshold
Mills and her colleagues said that the existence of minimum eliciting doses, or thresholds, for allergenic proteins “is now generally acknowledged, and data have now been generated and analyzed for a number of allergenic foods including peanut and soy.”
They noted that several commercially important fully refined vegetable oils are derived from the seeds of plants that are recognized as important food allergens – such as peanuts and soy.
However, full refining of oils should result in the almost complete removal of any potentially allergenic protein fragments.
“Little is known about the contribution of different processing steps to protein removal, although this information is crucial to risk assessment, particularly when considering process modifications,” said the researchers.
As such a method to determine the levels of proteins in refined oils would be of benefit, they added.
The team developed a method to extract and quantify residual proteins in refined oils, and tested the method on commercially available soy oil.
The results of the tests confirmed that while unrefined oils contain significant amounts of protein, full refining reduces the content by at least 100-fold, meaning that even the most sensitive allergy suffers would need to consume over 50 grams of refined oil before experiencing symptoms of an allergic reaction.
Source: Journal of Agricultural and Food Chemistry
Volume 59, Issue 5, Pages 1752–1759, doi: 10.1021/jf103560h
“Quantification and Partial Characterization of the Residual Protein in Fully and Partially Refined Commercial Soybean Oils”
Authors: N.M. Rigby, A.I. Sancho, L.J. Salt, R. Foxall, et al

5 comments (Comments are now closed)
Wowsers
Interesting article. Thanks for posting it. My experience is that often a reaction to an allergen is not immediate, and can take 10 minutes to several hours. Clinical studies are all fine and dandy, but in Real Life, it's a different story. I've tried products where "the protein has been completely removed during the process, therefore there will be no allergic reaction" and have reacted to the product.
Again, thanks for posting this, but now you have "The Rest of the Story" from myself and other posters I am reading in your comment section.
Report abuse
Posted by Mrs. Rivera
31 July 2011 | 04h54
Obviously Scientists Without Food Allergies!
I am allergic to soy and my daughter is allergic to corn. We both react significantly to those oils, even refined. For people who do not suffer from food allergies to publish that these things are not a problem is a disservice to those who do and know the truth. I take away from the article that the scientists involved are being paid by the food industry to conduct their research since the untruths benefit the industry.
Report abuse
Posted by Michelle
28 July 2011 | 23h58
Not True!!
This idea is just not proven in "real life" where allergic people DO react to items "with the protein removed" even though you may say we don't. I think there may be something else we are reacting to in these "protein removed" refined products that are still allergenic. If it's not a constituent that has been already identified by science, that doesn't mean it does not exist. I definitely have had allergic reactions to products where "all the protein has been removed" on numerous occasions, and to my body it doesn't matter what the experts say, it still is painful and severe and I have to live through it anyway.
Report abuse
Posted by Dottie
28 July 2011 | 23h49
Removing the proteins of an allergen don't help
So many mis-informed or simply uninformed scientists who don't have first-hand experience with food allergies think that removing the protein of an allergen removes its hazard. Not so. Those of us who live with food allergies 24/7 know all too well that removing the proteins of the offending food does NOT render it harmless.
Report abuse
Posted by Kay
28 July 2011 | 22h59
Refined oils can cause allergic reactions
I am allergic to corn and I most certainly do react to refined corn oil, even in trace amounts. I've also had serious reactions to refined canola oil. I have not reacted to any other kinds of oil, whether refined or unrefined. I have had to contact companies to find out if they use corn or canola oils during production of their products. This article favors the food industry, at the expense of people who actually have food allergies. We are the real experts, and know what we do or do not react to. And many of us 'do' react to refined vegetable oils, if we are allergic to that particular food.
Report abuse
Posted by Donnie
28 July 2011 | 21h43
Read all comments (5)