Canned beans are nutritionally problematic because they are not soaked to reduce phytic acid, yet the high heat processing reduces phytase so there's no hope of reducing it through other means.
Dry beans can be prepared so as to minimize the phytic acid and even the lectin content and are a more frugal way to add beans to your diet.
The problem is, dried beans aren't convenient. They involve planning ahead, so you can't just make some bean-layer dip right now. Maybe you have a hankering for chili, but didn't start soaking beans two days ago.
I am going to share with you a kitchen tip that will make cooking dried beans just as convenient as canned beans - and it's easy! In 5 minutes a day for a week, I make enough cooked beans to last for MONTHS!
nutritional issues
I just wrote about phytic acid and lectins in my post about growing corn and corn nutrition, so will just quote myself.
phytic acid
Phytic acid is an anti-nutrient that binds minerals, preventing their absorption. The traditional ways to minimize phytic acid are summarized by "Price People" as including soaking, sprouting and sourdough. Soaking grains, nuts and legumes in acidified water activates the grain's own phytase enzyme to break down phytic acid. Sprouting changes many of the nutritional factors as well as reducing phytates, making the grain more like a vegetable than a grain. The activity of yeasts and bacteria in fermentation breaks down phytic acid, but sourdough is particularly useful with a rye-based starter since it provides phytase.
For beans, the best method of reducing phytates is to sprout them, but for my easy, fast method we are going to settle for soaking. It may not be ideal, but it beats the heck out of canned beans.
lectins
Lectins are a class of proteins present in high levels in grains, nuts and legumes that are "sticky". Lectins bind to the villi of the GI tract, thus causing leaky gut and all it's associated autoimmune ills; there is also some evidence that lectins cause leptin resistance, which precedes insulin resistance and thus leads to T2 diabetes. Again, soaking, sprouting and sourdough are the primary methods of reducing lectin content in foods, and it appears that pressure cooking largely eliminates it, but the simplest method is to limit intake.
Again, while the preferred method is pressure cooking which eliminates virtually all lectins, my method is a compromise that involves a long, slow cook in a crockpot.
All the "Canned" Beans You Can Eat in 5 Minutes per Day
First, pick your favorite beans - we like navy, pintos, cannelloni, butter and black beans best - and go buy some.
Now, each night when you're doing dinner stuff, set up a couple cups of beans to soak. Rinse the beans, put in a big bowl, and for each cup of beans, add a TB salt, a TB of lemon juice or vinegar and a quart of water. Cover the bowl to keep dust and bugs out. Do this while doing dinner/dishes; it takes about 2 minutes.
In the morning, drain the beans, rinse and put in a crockpot (or stockpot, but then you have to be home to babysit it). Add 3 cups of water for each cup of beans you started with. If you have hard water, add a pinch of baking soda so they don't take forever to soften. Don't season them, and if you use broth instead of water, use something with a mild flavor. The point here is you're going to have beans to cook with, not as a dish in itself. Cook on low until dinnertime.
If you're too tired or busy to start the beans in the morning, that evening when you see your neglected beans, drain, rinse and soak again. If you soak for several days, worse that happens is they sprout, which just increases the nutritional value and reduces the anti-nutrients even further. Lazy can be a good thing!
If you did manage to get them cooked, spoon the mixture of beans and their liquid into pint-sized containers and freeze. You'll get 3 pints of cooked beans for every 2 cups of dried beans you started with. Then take a few minutes to start another batch soaking.
A pint-sized container of cooked beans is close enough to a "can" that they'll work in all ordinary recipes calling for beans.
In a week, with just a few minutes morning and evening while you're in the kitchen anyway, you'll have a wide variety of your favorite beans pre-soaked, pre-cooked and ready to use in any recipe. Viola!