# What happens to Gluten in a deep fryer? (Allergy related) **URL:** \ **Category:** Factual Questions\ **Created:** [January 28, 2011, 5:03am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272 "2011-01-28T05:03:47Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Amblydoper](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@Amblydoper](https://boards.straightdope.com/u/Amblydoper)\ **Post date:** [January 28, 2011, 5:03am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/1 "2011-01-28T05:03:47Z")
I work in a restaurant, and it seems “gluten allergies” are trendy these days. I get all these people freaking out about the tiniest trace of gluten that could be in something (maybe) and the web isn’t much help in sorting out the facts. So, could you smart Dopers help me out with a few things? Now, for the disclaimer: I understand what celiac disease is, and I respect that those affected by it need to avoid gluten at all costs. Because of this It is important to know which foods can be called “gluten free” and which cannot. Now for my question. If I cook a gluten free food in a deep fryer (say french fries) that has previously had gluten based foods in it (say battered fish), are the french fries still gluten free? Lets assume for the sake of convenience that the two foods had not been in contact in any other way, and separate utensils were used in preparation. The only source of gluten contamination could be the fryer oil. Can gluten survive the 350˚F of the deep fryer, and cause a problem for a celiac sufferer? Now, I picked french fries, as an example, but the web is full of tales of french fries that contain gluten. Please assume for this question that the french fries we are using are gluten free. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [January 28, 2011, 6:06am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/2 "2011-01-28T06:06:30Z")
I don’t know the answer to your question, but the apparent increase in complaints about gluten may not be altogether unwarranted. The prevalence of undiagnosed Celiac Disease has increased dramatically in the US in the past 50 years, possibly due to the fact that the high-gluten “dwarf” variant of \*Triticum Aestivum \*now accounts for over 99% of the wheat grown here today. Gluten is by far the most toxic of the commonly consumed foods in the US. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 28, 2011, 8:52am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/3 "2011-01-28T08:52:10Z")
> [@Amblydoper](#): > > Can gluten survive the 350˚F of the deep fryer, and cause a problem for a celiac sufferer? Well, when I bake bread gluten survives the 400 F of the oven for at least 20 minutes, so yes, gluten can survive in a deep fryer If a food with gluten - say something battered with a wheat-based coating - is fried in the deep fryer bits of that breading could wind up in the deep fryer fat and potentially get onto whatever is dunked into it next, such as up-until-then gluten-free french fries. So, if you’re cooking gluten-containing foods and non-gluten foods in the same deep fryer fat either the gluten free stuff goes first or you’re looking at cross contamination. Yes, for the very sensitive this could cause a problem. > [@Surreal](#): > > Gluten is by far the most toxic of the commonly consumed foods in the US. OH, BS - gluten is “toxic” only if you have celiac or an allergy. To everyone else it’s a healthy form of protein. If you’re looking for “toxic” start with things like excessive alcohol consumption. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 28, 2011, 2:37pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/4 "2011-01-28T14:37:22Z")
Apparently Celiac disease is brought on by allergy to [certain gluten peptides.](http://www.livescience.com/health/celiac-disease-gluten-peptides-100721.html) Now when you toss something organic into a deep fryer, it _will_ emit liquids and suspended solids into the frying oil. Put something glutenaceous in hot oil, and you _will_ end up with free gluten in your oil. 350°F isn’t all that hot as far as a protein is concerned. Witness the existence of such foods as bacon or fryed chicken as proof that high temps aren’t instant death for proteins. 500°F will destroy many organics quickly, but not 350°F. So whatever gluten leaches out of your wheat batter will have some sort of half-life in the fry oil. Since it’s the sequence of the peptides (eg Arg-Glu-Pro-Ala-Ala-Trp…) that matter in terms of allergy, and not the protein structure, that half life is likely to be at least on the order of minutes, and possibly in the range of hours to days. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 28, 2011, 6:26pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/5 "2011-01-28T18:26:12Z")
CELIAC DISEASE IS **NOT** AN ALLERGY! Gah! Please don’t spread information that is just flat out _wrong_. An allergy is an inappropriate reaction mediated by the IgE antibody. Celiac is an autoimmune disorder of the small intestine that in the presence of gluten causes atrophy of intestinal vilii. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 28, 2011, 7:14pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/6 "2011-01-28T19:14:13Z")
> [@Broomstick](#): > > information that is just flat out _wrong_. Kindly bite me. Those of us who aren’t students anymore don’t need to use the term in the precise fashion required to pass prof whatshisname’s test. And when we don’t, we’re NOT being “flat out wrong”, we’re just not being persnickety and obsessive. Here’s a more commonly used def: [allergy](http://www.merriam-webster.com/dictionary/allergy) See, it’s pretty general, and that’s how I was using it. Now tell us all about the halflife of immunoactive peptides in hot grease, if you can. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [January 28, 2011, 7:35pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/7 "2011-01-28T19:35:32Z")
> [@Surreal](#): > > Gluten is by far the most toxic of the commonly consumed foods in the US. Bullshit. By that metric (anything that causes a negative reaction is toxic), histamine is the most toxic substance around. (Please refrain from claiming histamine is toxic. There are limits around here.) ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [January 28, 2011, 7:49pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/8 "2011-01-28T19:49:47Z")
> [@Squink](#): > > Kindly bite me. **MODERATOR SUGGESTION** Dial it back a notch. This is GQ. **samclem** Moderator ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 28, 2011, 7:54pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/9 "2011-01-28T19:54:55Z")
> [@Squink](#): > > Those of us who aren’t students anymore don’t need to use the term in the precise fashion required to pass prof whatshisname’s test. If this were just any website I wouldn’t care, but we’re supposed to be fighting ignorance here. And it’s not an idle difference - if you enter an ER saying you have an “allergy” gets you a different reaction than saying “I have celiac”. They are two separate disorders. It’s like saying a heart attack and a stroke are the same thing because they both involve the cardiovascular system. They’re not. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 28, 2011, 8:34pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/10 "2011-01-28T20:34:18Z")
> [@samclem](#): > > **MODERATOR SUGGESTION** > Dial it back a notch. This is GQ. Let **Broomstick** dail it back a notch. He wants to get all prim and accusatory, I’m going to answer him. **Broomstick** , we’re not in an ER, we’re in GQ. ER language rules don’t apply here anymore than courtroom evidence rules apply i the Pit. Dial it back a notch, and look up the AA composition of the active subsequences and tell us if they contain any amino acids that are particularly prone to oxidation. That’d go towards actually answering the question posed in the OP. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 28, 2011, 9:09pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/11 "2011-01-28T21:09:58Z")
The OP’s question has already been answered. The answer is that cross contamination of foods cooked in a deep fryer that has had gluten containing foods cooked in it is a reasonable expectation. You, are on the other hand, said two medical disorders are identical when they are not. Maybe you don’t care, but I don’t want those wandering past to take as fact something that is incorrect. ---
**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\ **Post date:** [January 29, 2011, 12:45am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/12 "2011-01-29T00:45:26Z")
> [@Squink](#): > > Let **Broomstick** dail it back a notch. > He wants to get all prim and accusatory, I’m going to answer him. Her, FTR. > [@Squink](#): > > **Broomstick** , we’re not in an ER, we’re in GQ. ER language rules don’t apply here anymore than courtroom evidence rules apply i the Pit. Conflating a disease and an allergy is bad grammar? ---
**Author:** ![Dangerosa](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Dangerosa](https://boards.straightdope.com/u/Dangerosa)\ **Post date:** [January 29, 2011, 12:58am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/13 "2011-01-29T00:58:34Z")
If someone has a gluten intolerance - and especially if they have a wheat allergy or celiac (two different things - actually THREE different things) fry oil that has been used to fry gluten containing stuff (onion rings) has been contaminated. For the individual in question, that may or may not matter, but trace amounts of gluten are sufficient to cause a reaction in many people. In your restaurant, you have a few choices. If anyone says they have issues with gluten, say that your fry oil is used for gluten containing foods and let them make their own choice. OR have separate oil set up - if you are seeing a lot of gluten intolerant folks, saying “we have a separate fryer we use that we don’t use except for gluten free foods” will win you a lot of loyal customers. ---
**Author:** ![Amblydoper](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@Amblydoper](https://boards.straightdope.com/u/Amblydoper)\ **Post date:** [January 30, 2011, 3:58am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/14 "2011-01-30T03:58:06Z")
Thank you for the responses. I was hoping to hear that a protein in a deep fryer would break down enough to eliminate its allergy causing qualities, but i see now that it does not. Dangerosa, my official stance on fried foods and gluten concerns at this point is “if you have a severe gluten intolerance, we suggest that you avoid all deep fried foods.” I would love to add a third fryer to my line, but I don’t have room. Broomstick, Normally, bread is baked to an internal temperature of 180˚F. I was asking about gluten existing at 350˚F, so I don’t see how your first statement is relevant. Also, saying “Gluten allergy” and “celiac disease” in a hospital may get you different reactions, but not in a kitchen. For the purpose of this question, they are the same thing. ---
**Author:** ![Postariti](https://avatars.discourse-cdn.com/v4/letter/p/b4bc9f/32.png) [@Postariti](https://boards.straightdope.com/u/Postariti)\ **Post date:** [January 30, 2011, 5:11am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/15 "2011-01-30T05:11:39Z")
Amblydoper - I have severe Celiac disease, and your answer is exactly what I would want to hear. I want to be steered away from anything “risky.” People being people, you will probably have someone complain. But I think you’ll find most people will be grateful that you warn them. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 30, 2011, 7:01pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/16 "2011-01-30T19:01:13Z")
> [@Amblydoper](#): > > Also, saying “Gluten allergy” and “celiac disease” in a hospital may get you different reactions, but not in a kitchen. For the purpose of this question, they are the same thing. Well, if someone has celiac and they accidently eat some it may make them miserable, but it’s not considered a medical emergency. If someone with a gluten _allergy_ eats gluten it could potentially kill the person within minutes if the reaction is severe enough. So yes, the difference isn’t trival when you’re talking about potential consumption. Though yes, for the question of “does gluten survive the deep fryer” it’s not so important. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [January 31, 2011, 6:42am UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/17 "2011-01-31T06:42:50Z")
> [@Broomstick](#): > > OH, BS - gluten is “toxic” only if you have celiac or an allergy. To everyone else it’s a healthy form of protein. If you’re looking for “toxic” start with things like excessive alcohol consumption. Alcohol is toxic enough that it can kill you if you were to force yourself to drink a massive amount of it, but the same is true of water. Excessive consumption of alcohol can cause fatty liver disease, but so can drinking excessive soda/fruit juice (fructose). And just about all of the epidemiologic evidence I’ve seen suggests that moderate drinkers are healthier than teetotalers. Celiac disease is characterized by antibodies to two components of the gluten compound (alpha-gliadin and transglutaminase). But wheat gluten contains several other potentially toxic forms of gliadin (beta-gliadin, gamma-gliadin, omega-gliadin, etc.) that currently are not tested, so Celiac disease and gluten sensitivity appear to be underdiagnosed: > **[Finer Health and Nutrition : Educational Information : Frequently Asked...](http://www.finerhealth.com/Educational_Info/Gluten_Sensitivity/#What_is_gluten)** > > A website devoted to intestinal disorders caused by gluten, as well as gluten-free living. Offers health and nutritional counseling as well as a wealth of educational information based on facts and medical research. > [@](#): > > What is gluten sensitivity and how is it diagnosed? > Gluten sensitivity implies that there is an ongoing immune reaction to gluten in the diet, usually detected as antibodies against a subprotein of gluten called gliadin. **Although recently these antibodies were looked for only in the blood and are found in 12% of the general American public, my research has revealed that these antibodies can be detected in the stool in as many as 35% of what are otherwise normal people (U.S. and International patents pending). If high risk patient populations are tested, or people with symptoms, the percentage usually exceeds 50%.** It makes sense that the antibodies are more easily detected in the intestine because the immune system reaction to food is mainly a response occurring inside the intestinal tract. Thus, the end product of intestinal transit, stool, is the most logical (albeit more messy) place to look. This is the rationale of the new test developed by a laboratory set up by Dr. Fine to serve the testing needs of celiac patients. One in three doesn’t sound like very good odds to me. More on gluten toxicity here: > **[Non-celiac gluten sensitivity](https://en.wikipedia.org/wiki/Gluten_sensitivity)** > > Non-celiac gluten sensitivity (NCGS) or gluten sensitivity is a controversial disorder which can cause both gastrointestinal and other problems. > NCGS is included in the spectrum of gluten-related disorders. The definition and diagnostic criteria of non-celiac gluten sensitivity were debated and established by three consensus conferences. However, as of 2019\[update\], there remained much debate in the scientific community as to whether NCGS was a distinct clinical disorder. > The pathogenesis of NC... > [@](#): > > **Gluten toxicity: An increasing number of studies on gliadin indicate gluten has a direct and modifying effect on the cells of the small intestine. Two different lines of research show that different gliadins can increase permeability of the epithelial cells (outermost cells of the villus) allowing food proteins to enter. One study examined the effect of ω-5 gliadin, the primary cause of exercise/aspirin induced anaphylaxis, and found increased permeability of intestinal cells caused by this gliadin and another wheat albumin.[17] Another line of research shows gliadin binds a chemoattractant receptor and causes increases of a factor that destroys tight junctions.[18] These junctions prevent leakage around the cells that line the small intestine, resulting in the leaking of food proteins into the body.[19] These toxicities of gluten that are not part of the adaptive immune response may be the link between wheat and gluten sensitivity, and possibly type 1 diabetes**. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 31, 2011, 1:09pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/18 "2011-01-31T13:09:13Z")
Aside from my question on the soundness of your sources, NONE of that contradicts my statement that gluten is only “toxic” if you’re sensitive to it. Most adult human beings, when you look at the entire world, can’t digest lactose, yet here in North America there’s milk and milk products everywhere. OMG! We’re bing poisoned! Um… no we’re not. If you can digest milk as an adult go ahead and eat it. If you can’t, don’t. Same thing for gluten. If you can eat it without a problem go ahead. If you’re sensitive to it, don’t. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [January 31, 2011, 2:52pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/19 "2011-01-31T14:52:35Z")
> [@Squink](#): > > Apparently Celiac disease is brought on by allergy to [certain gluten peptides.](http://www.livescience.com/health/celiac-disease-gluten-peptides-100721.html) > Now when you toss something organic into a deep fryer, it _will_ emit liquids and suspended solids into the frying oil. Put something glutenaceous in hot oil, and you _will_ end up with free gluten in your oil. > 350°F isn’t all that hot as far as a protein is concerned. Witness the existence of such foods as bacon or fryed chicken as proof that high temps aren’t instant death for proteins. 500°F will destroy many organics quickly, but not 350°F. So whatever gluten leaches out of your wheat batter will have some sort of half-life in the fry oil. Since it’s the sequence of the peptides (eg Arg-Glu-Pro-Ala-Ala-Trp…) that matter in terms of allergy, and not the protein structure, that half life is likely to be at least on the order of minutes, and possibly in the range of hours to days. Exactly. The protein may [denature](http://en.wikipedia.org/wiki/Denaturation_%28biochemistry%29), in that it will uncoil and cease to function as it normally does, but the actual chain is unlikely to [hydrolize](http://en.wikipedia.org/wiki/Hydrolyze#Hydrolysis_of_peptide_links), especially in the not-so-wet environment of a fryer. Well, there is moisture in the food, but still 350 °F isn’t all that hot. ---
**Author:** ![omega2498](https://avatars.discourse-cdn.com/v4/letter/o/9de053/32.png) [@omega2498](https://boards.straightdope.com/u/omega2498)\ **Post date:** [February 24, 2011, 11:49pm UTC](https://boards.straightdope.com/t/what-happens-to-gluten-in-a-deep-fryer-allergy-related/569272/20 "2011-02-24T23:49:38Z")
It has affected me personally - I was diagnosed via Endoscopy in 2003. If I eat Fries (chips in the UK) that are contaminated cue 10-12 visits to the toilet and 4 days of stomach cramps. not nice ☹