The FODMAP content of different varieties of corn/maize and their derivatives

low fodmap, maize, corn, gluten free, irritable bowel syndrome, IBS, fructose malabsorption, corn syrup, high fructose corn syrup, corn starch, corn meal, cornflour, popcorn, sweet corn

For a grain that is used in so many gluten free/IBS friendly recipes and products, corn tends to be a topic of contention in terms of FODMAPs. But why? It’s gluten free (unless contaminated with the protein through processing methods), that much we know, but why do some people react to corn and others not, or, even more confusing, why do different types of corn cause issues for an individual when others are well tolerated?

One of the obvious answers is that all of us react differently to different fermentable carbs, which is true – but it goes deeper than that. The problem with corn is simple – corn is not simple at all. People have sensitivities, intolerances and allergies to different aspects of corn, and not all corn is created equal. This article will deal with the fermentable carbohydrates that corn can contain, as corn allergies and intolerances are not within the scope of this blog. If you are concerned that you have an allergy to corn, please see your doctor.

Since the Native Americans domesticated corn thousands of years ago, it has been extensively bred into many varieties, all of which contain different amounts of FODMAPs, as well as different physical characteristics that lend themselves to certain uses in cuisine and industry. Obviously, for the purpose of this article, I will stick to the species of corn that are intended to be eaten.

Genetic Modification

This needs to be said. Corn is commonly found as a genetically modified (GMO) product. You may choose to consume non-GMO varieties of corn for personal beliefs, however, genetic modification does not affect FODMAP content. Unless a variety of corn is bred to contain large amounts of fructans, or have a higher fructose:glucose ratio than sweet corn (etc), the GMO corn you find at the supermarket will have the same recommended safe serving size as it’s non-GMO counterpart.

Sweet Corn/Corn on the Cob

Variety: sweet corn.

FODMAP rating: safe in 1/2 cob servings.

Sweet corn is the corn we eat prepared as a vegetable – on the cob, or find tinned in the grocery store. It is picked when immature, before the simple sugars have a chance to convert to starches. Delicious with butter, salt and pepper, it unfortunately has a very close fructose:glucose ratio, as well as a large amount of sucrose, so should therefore be limited to half-cob servings, according to Monash University. Of course, if you know you can eat more without reacting you may continue to do so.

Corn Meal, Polenta/Grits and Popcorn

Variety: dent and flint corn.

FODMAP rating: safe in 1 cup servings.

Corn destined to be consumed as a grain is picked and processed once it has matured, which means the water content in the endosperm is greatly reduced and the simple sugars have largely been converted into starch. Starch is not a FODMAP, which means that products made from corn meal, polenta and popcorn kernels (such as corn tortillas, corn bread and mamaliga) are safe in terms of fermentable carbohydrates, as long as no other FODMAP-containing ingredients have been included in the recipe.

Dent corn has a greater water content than flint corn, which has a much harder, less digestible endosperm; this is due to the differing amounts of floury vs vitreous starch (see Figure 3). For this reason, they are turned into corn meal/polenta and popcorn, respectively.

Cornflour/ Corn Starch

Variety: waxy corn.

FODMAP rating: safe.

Waxy corn contains a different type of starch (amylopectin, rather than the amylose found in the previously mentioned corn varieties), and is more effective as a thickener and stabilising agent in foods. This product doesn’t come from the entire corn kernel but is the isolated amylopectin.

Corn Syrup

Variety: dent corn (amylose starch).

FODMAP rating: safe but use in moderation.

Consisting of approximately 93-96% glucose (in the form of maltose, a disaccharide of two glucose molecules), corn syrup is considered safe in terms of FODMAPs, though it should still be consumed in moderation, as it is a sugar and very high GI. Corn syrup is produced via a multi-step enzymatic process, which breaks the corn starch down into varying products, including maltose. Corn syrup is available in light and dark varieties; the dark corn syrup is mixed with some molasses, which, while it has a slightly elevated fructose:glucose ratio, should be evened out by the extremely concentrated glucose in the corn syrup.

In the USA, corn syrup is synonymous with glucose syrup, as glucose syrup is nearly always made from corn. In other countries, glucose syrup can be made from wheat, rice, potatoes or tapioca.

High Fructose Corn Syrup

Variety: dent corn (amylose starch).

FODMAP rating: high, avoid.

Once corn syrup (which is mostly maltose/glucose) has been produced, the reaction is taken a step further and the corn syrup is processed with the enzyme glucose isomerase, to convert some of the glucose into fructose. This produces HFCS-42. Liquid chromatography is used to further convert glucose into fructose, to create HFCS-90, which can be blended with HFCS-42 to create HFCS-55.

Regardless of your opinion of the health dangers of HFCS, it is NOT low FODMAP. As the varieties (42%, 55% and 90% fructose) are not labelled differently, it’s best to stay clear.

Other names include: isoglucose, glucose-fructose syrup, fructose-glucose syrup, isolated fructose and fructose syrup (the latter two refer to HFCS-90).

Corn/Maize Oil

Variety: made from the germ of corn kernels.

FODMAP rating: safe.

FODMAPs are a variety of fermentable carbohydrates. Pure corn oil is 100% fat, so contains no carbohydrates, thus no FODMAPs and is safe to use.

So, there you have it. Different varieties of corn (maize) and their derivatives all have different FODMAP ratings; however, as usual, if your tolerances vary from what Monash has suggested is safe, follow your gut.

Disclaimer: I am not a dietitian or a medical doctor; I have just researched this topic myself. If your health professional has advised you to avoid corn, please do so, as it might not be for a FODMAP-related reason.

Title image credit goes to: http://pixabay.com/en/users/margenauer-271373/

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Cast Iron Cornbread – Low FODMAP & Gluten Free

Cast Iron Cornbread - Lower FODMAP

I had never eaten corn bread before moving to the USA, which isn’t really that surprising. I suppose back home our cheat’s bread is damper and many Americans wouldn’t have tried that, either.

The first corn bread I tried was a sweet version that I’m pretty sure had corn grits in it as well, judging by the texture. It was moist and chewy and sweet and delicious but really only a one trick pony. The savoury version you can use as sandwich bread, as the base to a stuffing, serve it with soup etc. Much more versatile.

The following recipe I based from reading about corn bread in general – to get an idea of ingredients, as well as the method. The website I found most useful was The Paupered Chef, as I particularly liked the idea of soaking the corn meal in the buttermilk (they used milk) beforehand. Some say that true Southern corn bread is 100% corn meal, others say that that’s untrue. Not being from the South, let alone the country, I have absolutely no opinion on what is or isn’t traditional, I’m just making what I find tasty.

FODMAP Notes:

  1. Corn is a tricky one. The FODMAP content depends on the variety; sweet corn can be troublesome for some with FM due to the high sugar content and some people are sensitive to GMO crops, of which corn is the poster child (I’m not going to enter the GMO debate here, though). However, the sweet corn that is grown for eating on the cob isn’t the same corn that is used for corn meals, flours or starches and it’s different again to corn that is grown for use in plastics and bio-fuels. Corn meal is not made from sweet corn, thus is much better tolerated. There are specific corn allergies, though, so watch out for those.
  2. Rye can be substituted in for the GF plain flour, if you can tolerate it. As I have mentioned beforestudies show that rye flour contains more fructans than wheat but evidence suggests that the chains are longer, thus taking longer to ferment. It is generally less of an irritant than wheat to those with FM, although many still have problems.
  3. If you have a gluten issue or are very sensitive to fructans, replace the rye flour with your favourite gluten free blend and 1/2 tsp. of xanthan gum (or 1 tbsp. chia seed meal).
  4. Buttermilk contains lactose, which is water soluble. If you malabsorb lactose then replace it with the same volume of LF milk with a dash of lemon juice.

Cast Iron Corn Bread

This quantity cooks well in a 12 ” cast iron skillet.

  • 2 1/4 cups corn meal
  • 2 cups buttermilk or lactose free milk
  • 1 1/2 cups rye flour OR a gluten free plain flour blend with 1/2 tsp. xanthan gum or 1 tbsp. chia meal
  • 1 tbsp. baking powder
  • 2 tsp. kosher salt
  • 3/4 cups unsalted butter, softened
  • 2 large or 3 small eggs
  • Optional – 1/4 cup roughly cut fresh herbs, such as rosemary

Combine the corn meal and buttermilk in a large mixing bowl – everything will end up in here eventually – and let it sit for 10 minutes. Meanwhile, preheat the oven to 230 C/450 F. Place your cast iron skillet (or any skillet with an oven safe handle, the heavier its base the better) in the oven to heat up. Please remember to now use gloves whenever you handle the skillet!

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While the corn meal is soaking, sift the flour (with any necessary xanthan gum or chia meal), baking powder, salt and the optional herbs into a separate bowl, and combine the eggs and softened butter (the softer, the better) in another.

When the corn meal and buttermilk have been sitting for the ten minutes, add in first the wet ingredients and then gradually add and mix in the dry ingredients – depending on your particular flours of choice, etc, you may or may not need all of it. The mixture should resemble a thick cake batter.

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Now, take the skillet out of the oven and grease it up with either a dollop of butter or olive oil, or even lard – I used butter. Spread your lipid of choice all around the base and at least half way up the sides of the pan and tip out any excess. Plonk the batter (it is too thick to pour) into the waiting skillet, make sure it is evenly spread out and pop it in the oven.

Baking instructions:

  • 12″ cast iron skillet – 25 minutes at 230 C/450 F.
  • Loaf tin – 50 minutes at 180 C/350 F (until a skewer tests clean).

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Let it sit in the skillet for 10 minutes to cool slightly and then turn it out onto a wire rack. Let it sit for half an hour before cutting, or it may crumble. This corn bread works well as sandwich bread (in a loaf pan), served with soup etc, it goes very well with my cranberry sauce/jam and can be used in a corn bread stuffing, the recipe for which I will be posting next. Stay tuned!

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