Several sources have claimed that canned beans (after discarding the water in the can) are significantly lower in FODMAPs, particularly galacto-oligosaccharides, compared to cooked dried lentils. I'm interested in reducing galacto-oligosaccharides as a way of reducing flatulence and indigestion symptoms.
For instance, https://www.glnc.org.au/resources/hot-topics/how-to-enjoy-legumes-on-a-low-fodmap-diet/ seems to claim a two-fold reduction:
Canned legumes are much better tolerated than dried legumes, due to having a lower FODMAP content. Canned lentils are safe at 1/2 cup, whilst butter beans and chickpeas are low FODMAP at 1/4 cup. Keep in mind that if you choose dried over canned, it is likely the same portion won’t be tolerated if you are sensitive to GOS.
Dried red and green lentils: dried lentils require a little more prep and will take some time to cook prior to being ready to eat. Keep these to 1/4 cup serve of cooked lentils – they’re are a fabulous addition to curries and soups!
Lentils may be cooked without prior soaking, but presumably cooking dried chickpeas involves soaking them, which should reduce the galacto-oligosaccharides. Why would canning reduce this process further? Could soaking the dried legumes for a longer period of time and replacing the water a couple times reduce the FODMAPs to the same level as canned beans (maybe in the fridge to prevent bacterial growth)? Maybe I should soak the beans, cook them, and then soak them further? Or is there something else special about the canning process compared to using dried beans?
