Is There Gluten in My Lemons? Soy in My Apples? What’s in Waxed Produce?

I was recently told by a friend that her friend kept reacting to something even after she went gluten-free. She finally decided it was the lemons she was using in her gluten-free cake. Lemons?  My mind raced.  Ohhhh – wax? Is that what’s been bothering me lately? It seems as though I’ve been reacting to everything these days, AND I have gotten into this crazy lemon zest phase where I seem to put it in everything, from drinks to gremolata, to salad toppings.  Could this really be the problem? And if it were lemons that were causing me these problems, could there be gluten in waxed produce? Apples, zucchini, peppers? In a few split seconds I had a minor (internal) meltdown as I began to wonder, is nothing sacred? Is there not one piece of food left that gluten hasn’t found its way into?

Is there gluten in waxed produce? Find out: #glutenfree #celiac #glutensensitivity Click To Tweet

So I went to the FDA’s website and found a page from 2007 called Questions and Answers on the Gluten-Free Labeling Proposed Rule, question #14. “Are there examples of food products that are naturally ‘gluten-free’”? Among the few foods listed in response, were fresh fruits and vegetables, of course. But only “fresh fruits and vegetables that are not coated with a wax or resin that contains gluten.” Well how do I know if there’s gluten in waxed produce or not?

Then, I stumbled upon this article by Dr. Vikki Petersen, about possible soy and dairy in my waxed produce!  Both of those are also bad news for me!

I then called my local Whole Foods where I buy organic apples and asked them if organic produce is waxed. Maybe at least, I could avoid possible food allergens by going the organic route. I always buy organic apples, since they are on the Environmental Working Group’s Dirty Dozen list of produce on which pesticides are used the most. The response from the grocer is that they aren’t supposed to be waxed, but he has seen many an organic item with wax on it. Hmmm.

Lemons, on the other hand, are not on the Dirty Dozen list and so I don’t usually buy them organic (the non-organic ones are usually much cheaper, and often juicier as well).  So I thought I would test my non-organic lemon zest for gluten, to see if I could get closer to an answer on this.

I asked two companies if I could try out their at-home gluten-testing kits, and both GlutenTox Home, and EZ Gluten were kind of enough to send me some tests to review. Both brands come with two tests in them (or you can get more if you have that kind of money to spend).  I’m glad I got four tests, because I did the first one wrong. Its just a matter of reading the directions correctly, and its pretty straightforward, but with little sleep the night before, and chattering pre-K kids in the background, I put the sample in the wrong vial. Eek! There goes $16.00! If you want to test at home, I highly recommend doing it in a quiet place where you can concentrate. 🙂

By the way, I was later informed by GlutenTox Home that it is also possible to just test the surface of a food, by opening the test and rubbing the soft part onto the food. Even though its not in the instruction booklet that comes with the test, they do have detailed instructions on their website.

I did the second test correctly and I held my breath as I waited for the results. The last time I read such a stick, I was waiting for news that I would be adding another member to our family! Part of me was hoping the results would test positive. I wanted to find the source of my illness. But then again, it would be devastating to know that I could no longer eat waxed produce. After waiting the full ten minutes, the blue line showed negative for gluten.

I guess that’s good. And since my lemons were not organic, I figured they had a higher chance of containing gluten then my organic apples. I don’t know why I assumed this. But with only two tests remaining, I had to move onto to something different. I tested walnuts next, which I consume a healthy dose of every morning for breakfast.  Walnuts, like other nuts, could also be waxed. And these particular walnuts could also be cross-contaminated since they are processed on equipment that are made in a facility that also process milk, wheat and soy.  So I ran them through my food processor and tested them for gluten, too. And again, the test results came back negative.

Is this good news?  Or are the tests inconclusive? In order to test accurately, you have to break down the food small enough. Lemon zest and processed walnuts should be small enough to test. But what about “hot spots”? One cannot be sure that if there is gluten, that it is spread evenly throughout the food, and that the sample picked it up. This is a notorious problem in testing for gluten, which is why manufacturers of gluten-free foods have a much more rigorous testing process than what I am trying at home.  But I did mix the samples around a lot, so hopefully if it were there, I would have found it.

So maybe there really isn’t gluten in my lemons and walnuts. But what about dairy and soy?

I then asked a food scientist with expertise in testing food for allergens at the Institute of Environmental Science and Research in New Zealand if there was a way to test for dairy and soy in our food. He directed me to a couple of commercial testing laboratories, in which you can send in a sample. But the cost of doing such a test is a bit much for personal use. Also, soy is apparently very hard to test for, and usually only takes a very miniscule amount for someone to have a reaction to. But in his opinion, he thought it was unlikely that dairy, soy or gluten would be found in wax coatings anyway.

Not one to take just one person’s word for it, I turned to the internet for more insight. An older article by Rabbi Heber explains that the waxes most often used on produce are made from beeswax, carnauba (a Brazilian palm tree), and shellac (or lac resin) from the lac beetle. Startlingly, it also stated that lac resin often has to be mixed with soy or casein proteins to make it thicker, but that carnauba and beeswax are already thick enough and don’t require any other additives.

Also, most of what I read was that organic produce can indeed have wax on it, but it can only be made from natural materials. The question remains as to whether or not shellac is considered a natural material. Shellac is the resin secreted by the female lac beetle, much like honey comes from bees. It is Generally Regarded As Safe (GRAS) by the FDA, and is natural until it is processed after which it can be used for a variety of things, from coating fresh fruit, to polishing wood cabinets. Vegans have a big problem with eating shellac resin. But there doesn’t seem to be any reports on the ill-health of shellac itself. Anyway, that’s another issue.  A call to the USDA’s National Organic Program told me that shellac canbe used in organic produce. So only choosing organic produce would not be the solution to avoiding these allergens.

I called Rabbi Heber because although I know that the he did his homework, and that Kosher and Pareve certification is serious in Jewish religion, I was still not satisfied that this was the complete answer. As we discussed, his article was 15 to 20 years old, and so its not possible to know if the wax configurations he wrote about then, are the same today. In fact, he had tried to do some follow-up research on this article some years later, and could no longer find the companies that he had originally interviewed.

I still wanted someone to definitively state that there is (or is not) gluten in waxed produce (or soy or dairy). So I consulted the Codex Alimentarius which states that “waxes may be bleached, mixed with alcohol… treated with sulfuric acid (candelilla wax)…” None of which sounds particularly pleasing, but still nothing about gluten, dairy or soy.

I then contacted Dr. Jinhe Bai at the USDA’s Agricultural Research Service. He is an expert on the post harvest quality of fruits, including “edible coating technologies.” While he has seen research on all kinds of additives used in wax coatings, he says he has never seen gluten, dairy or soy actually used in commercial applications. He is an independent researcher, not working for a manufacturer, so I didn’t see why he would stretch the truth. And he told me he will keep in touch in case he does see something different.

But still, produce comes from all around the world, and waxed coatings for produce come from many different manufacturers around the world. So I wanted to ask one more source: manufacturers themselves. I found a place where you can find wax coatings from wholesalers and pretended to be interested in purchasing their products. Because I have now learned that the only place my allergens might reside would be in a shellac wax, that is the only product I asked them about. As part of my inquiry, I told them I needed a wax that was free of any soy, dairy, or gluten proteins. As one manufacturer responded “Food grade bleached and dewaxed shellac is refined from granule shellac without protein, which means without gluten, dairy or soy.” That was good to hear. But do all companies comply with this definition? I haven’t heard back from the other companies yet.

Finally, I found this statement on the Rainer Fruit company’s website: “Wax sources generally are plants, food-grade petroleum products, or insects (similar to honey from bees). Some waxes can be made from dairy or animal sources, but we are not aware of any such coatings being used on fruits and vegetables in Mexico, the United States or Canada. This is particularly important for people following Kosher or vegetarian diets and who don’t want any animal-based wax on their produce. Any commodities that do have this type of coating must be labeled “Coated with animal-based wax.”

So based on my conversations and what I read, I would say that my there is most likely no gluten in waxed produce. It also seems that the use of casein and soy in waxes are extremely rare, especially in North America. And if there is an animal-based protein in the wax, it should be labeled as such.  Soy wouldn’t have to be labeled, but again it does not seem to be commonly used, commercially. And according to the FDA’s page on waxed produce, “each piece of waxed produce has only a drop or two of wax.”  So I would have to be super sensitive to be affected by an allergen in my waxed produce, if it even actually existed.

Of course, anything is open to cross-contamination. But that’s another issue.

I know this is not a resounding YES or NO to the question, which leaves me still a little unsettled, but for now I’m going to assume that waxed produce is safe. So that’s my take on the issue, but I’m open to discussing it more. Do you have information that I don’t? Please share it.

After all of this happened, I began to wonder if FDA will be labeling non-waxed produce. So I asked Jules Shepard from this and a few more questions about labeling. Stay tuned for that interview next week. In the meantime, its back to the drawing board for me as far as figuring out what’s been causing my food reactions. I think I might be honing in on it, but won’t bother you with the details until I do. [update from October 2014: I learned that I had “leaky gut” or intestinal permeability.]

And by the way, I have one extra gluten-testing kit left and I feel pretty certain that I am not being exposed to gluten in any of my household items. So I’m trying to decide what to test. I kind of want to see a positive result on the stick so that I know the test works. Is there anything you’ve ever wondered about – a brand, a bulk food, etc.? Let me know and I’ll test it!


  1. Heather,
    Thanks for doing such awesome research. I am doing the same for my readers. I need to know if there is corn in the coatings, as I have read that corn zein is sometimes used and understand that most ethanol is derived from corn. I want to link to this page for readers and need to do some additional digging for my corn free peeps. I did find an article from Rabbi Price written in 2007 who says most uses of dairy, gluten, and soy are in research and development and not in commercial use.

    Email me if you have additional info on corn or would like a linky with a quote from you in my article. I’d love to know who you were able to contact on the resins so I can do the same. My fear is that corn would be likely on the organic versions of the coating.

    • Hi Caryn,

      Sure, you can quote this blog post! I’m glad you found it helpful. I didn’t ask about corn, because personally, I didn’t have a problem with it. But now that I am on a paleo diet, and concerned about GMO corn, I would be curious to know what you come up with. I did speak with a person at ARS in in FLorida who said

      As I know, the major ingredients in commercial fruit and vegetable coatings are wax (carnauba and beeswax), resins (such as shellac) and lipids (such as vegetable oil) based. Gluten is not likely added in generally. I have never heard allergies caused by edible coating – wax in fruit or vegetable.
      You mentioned Table 1 in my book chapter, which is based on research reports, and most of them have not been and maybe will never be used as commercial coating. For the organic coating, I have not seen any gluten, dairy (casein) or soy in their ingredients. You can find the updated detail from the website of OMRI (

      If you want to ask him more questions, his name is Jinhe Bai.
      Thanks for getting in touch!

  2. Pingback: Fruit Wax Ingredients Revealed: What's on the Wax Covering Your Fruit? Healthy Family


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