Nutritional Benefit of Soaking Beans Prior to Cooking

Dried beans are a versatile, affordable source of protein, fiber, starches, iron, B vitamins, potassium, magnesium and other essential nutrients. When you prepare dried beans from scratch, you can avoid the sodium and other additives that canned beans contain. In addition to softening beans in preparation for cooking and shortening their cooking time, soaking beans may make them more digestible and enhance their nutritional benefits.

The outer coatings of many varieties of beans contain sugars called oligosaccharides. When beans aren't soaked, these sugars can bypass your stomach and small intestine without being fully digested. When these sugars enter your large intestine, bacteria break them down, producing intestinal gas in the process. Soaking dried legumes dissolves the membranes that cover beans and releases their oligosaccharides. After soaking, discard water and rinse beans to remove sugars. According to the Science of Cooking website, navy and lima beans have more gas-producing potential than most other varieties.

Soaking beans in water removes tiny particles of dirt, gravel and other debris. Beans go through threshing and cleaning processes before they're marketed to consumers. However, they are not washed because moisture would encourage sprouting. Soaking beans removes their coating of field dust, which may contain residue from pesticides or other contaminants. Before soaking, remove visible particles and sprouted beans. After you've soaked dried beans, drain and rinse them to remove the remaining contaminants and sugars.

Phytic acid, a compound in many legumes and grains, may reduce the bioavailability of zinc and other minerals, making it more difficult for your body to utilize these nutrients. Zinc is an essential element that supports cellular metabolism and promotes healthy neurological function, growth, immunity and wound healing. In an article published in the Sept. 2000 issue of the "Journal of Physiology and Biochemistry," Gloria Urbano from the University of Granada and co-authors reported that soaking legumes may reduce the effects of phytic acid on mineral absorption.

For every pound of dried beans, use 10 cups of water for soaking, the Centers for Disease Control and Prevention advises. Reduce soaking time by boiling beans for two to three minutes, and then removing beans from heat and leaving them covered for two to three hours. To remove gas-producing starches, boil 1 lb. of beans for two to three minutes, cover the pot and allow beans to soak overnight. This method removes 75 to 90 percent of the beans' indigestible starches, according to the CDC. While harder beans like navy beans, pinto and kidney beans require soaking, soft legumes like lentils, split peas and black-eyed peas may be thoroughly rinsed rather than soaked before cooking. Check the preparation instructions on the package before soaking or cooking beans.