Let’s talk about canned foods and FODMAP levels. We know that some of you are confused about how canned champignon (button) mushrooms can be low FODMAP – that’s not surprising, as button mushrooms are well known for being high FODMAP. The good news is that manufacturing processes, like canning, can significantly impact the FODMAP content of food. The type of food and the liquid it is stored in can influence the overall FODMAP level of canned foods. Let’s take a closer look:
How does canning the food decrease the FODMAP content?
FODMAPs are water-soluble carbohydrates. When a high FODMAP food is stored in water or brine the FODMAPs can leach out of the food and into the liquid. This leaching process can lower the overall FODMAP level of the food as some of the FODMAPs transfer into the water (1)..
However, it can be hard to predict if enough of the FODMAP content will leach out of the food to reduce the FODMAPs from high to low levels (2). The canned foods need to be tested by a FODMAP-trained laboratory to get accurate data on the FODMAP levels.
What high FODMAP foods become low FODMAP when canned?
Canned Champignon (Button) Mushrooms in Brine
Fresh button mushrooms are high FODMAP for mannitol and fructans depending on how much you eat (1). However, canned champignon mushrooms are a low FODMAP alternative and are popular in Asian cuisine. You can enjoy canned champignon mushrooms in 6 mushroom serves while on the low FODMAP diet (1). Just remember to buy champignon mushrooms in brine (not sauce) and rinse them well before using them.
Boiled lentils can contain moderate to high amounts of FODMAPs depending on the serving size, however, canned lentils are slightly lower in FODMAPs and can be enjoyed in ¼ cup serving sizes (1). In canned lentils some of the water-soluble GOS (oligosaccharides) and fructans leach out of the lentils into the water content lowering the FODMAP content (1). Always rinse canned lentils well before using.
Canned Chickpeas (Garbanzo beans)
Dried chickpeas are considered high FODMAP, however, their canned counterparts are lower in FODMAPs. Again the GOS in the chickpeas leaches out into the water in the can and lowers the chickpea FODMAP level. On the first phase of the low FODMAP diet you can enjoy a ¼ cup serving of canned chickpeas (1). Remember to rinse the canned chickpeas under running water before using them.
Canned Baby Corn
Baby corn is an immature ear of corn that is picked before it has a chance to mature. This ingredient is fantastic in soups in stir-fries and you can enjoy canned baby corn in 1 cup serves on the low FODMAP diet (1).
Does canning reduce the FODMAP content of all legumes/beans?
Some canned beans like butter beans, cannellini beans, black beans and red kidney beans also have small low FODMAP serving sizes that can be enjoyed (check the Monash University FODMAP Diet App for more information). While other canned beans like baked beans, borlotti beans, and four bean mix are still high FODMAP despite being canned. We recommend checking the Monash University FODMAP Diet App for more information.
What about canned fruit?
Monash University has yet to test a wide range of canned fruit. We do know that canned guava, apricots, pears and peaches are generally considered high FODMAP, although they do have some small low FODMAP serving sizes (check the Monash University FODMAP Diet App for information) (1). Canned pineapple in juice has a low FODMAP serving size and can be enjoyed in 90g (3 oz) servings (1).
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Be Aware of Canned Tomato…
Just before you throw two cans of plain crushed tomatoes into your spaghetti bolognese… be aware that canned tomatoes contain FODMAPs and they need portion control. According to the Monash App a ½ cup (100g) serving of canned roma/plum tomatoes is low FODMAP, however, larger servings above 1 cup can contain moderate to high levels of FODMAPs (1). This means you need to split a 400g (14oz) can of tomatoes between four serves. You can make your tomato pasta sauce go further by adding low FODMAP chicken stock, a little bit of tomato paste, and some cornflour/starch to thicken.
Watch Out For Sneaky FODMAPs
Avoid canned food that has added high FODMAP ingredients like onion, garlic, high fructose corn syrup, or high FODMAP fruit juices as these will increase the FODMAP content of the food.
Canning high FODMAP foods can reduce their FODMAP content, however, it is hard to predict if enough FODMAPs will leach into the water to make the food low FODMAP. This means we recommending checking the Monash University FODMAP Diet App to see if the canned food is low FODMAP before consuming.
1. Monash University App. Food Guide. The Monash University Low FODMAP Diet App. 2023: Version 3.0.11(439). Date retrieved: 2023-10-03. Retrieved from :http://www.med.monash.edu/cecs/gastro/fodmap/iphone-app.html. Accessed: 2023-10-03.
2. Monash University. FAQ: Does cooking breakdown certain FODMAPs in a way that would make them less problematic?. Monash University. 2015. Retrieved from:http://www.med.monash.edu.au/cecs/gastro/fodmap/low-fodmap.html#1. Retrieved on: 2016-07-31. (Archived by WebCite® at http://www.webcitation.org/6jQWuAIwQ)
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