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What Are Benefits of Soaking Beans? Dr Badran Answers

Thu 14 Mar 2024 | 10:57 PM
Dr. Magdy Badran
Dr. Magdy Badran

Fuul medammes is the dish of choice for Egyptians during Ramadan ¬and beyond. Beans nourish millions of people in developing and developed countries. It fulfills 28% of the carbohydrates, 34% of the dietary fiber and 25% of the protein dietary recommended intake values for an average healthy adult (18–65 years old). Beans are also a rich dietary source of minerals (e.g., magnesium, potassium, zinc, and copper) and vitamins (e.g., vitamins B1, B6, and folate).

Soaking of beans prior to cooking has been a method used for centuries all over the world. There are countless different ways to soak beans. The basic steps of soaking include placing the beans in a large bowl or jar, generously covering them with water and leaving them to soak for several hours.

How Long Should You Soak Beans?

Before cooking, all dried beans need to be rehydrated by soaking. The 10- to 12-hour overnight soak is the easy and always effective method, but you can quick-soak beans by bringing them to a boil for one minute, then covering the pan and letting them sit for one hour.

Beans soaked longer than 12 hours can absorb too much water and lose their characteristic texture and flavor. To store soaked beans, remove them from their soaking water and dry them thoroughly. Once dry, put them in an airtight container and store them in the fridge. The beans will be good for 4-5 days. If you want to keep them longer, you can freeze them.

Soaking Increases Digestibility

Soaking beans can help improve the texture of the final product once the beans are cooked and reduce the gas produced when the food is being digested.

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. Soaking dried legumes dissolves the membranes that cover beans and releases their oligosaccharides. After soaking, discard water and rinse beans.

Soaking Decreases Lectins Levels

Lectins are a family of carbohydrate-binding proteins. Lectins have received much attention as a major cause for obesity, chronic inflammation, and autoimmune diseases. They are found in all plants, but raw legumes (beans, lentils, peas, soybeans, peanuts) and whole grains like wheat contain the highest amounts of lectins.

Lectins are defined as proteins that bind to carbohydrates. The same features that lectins use to defend plants in nature may cause problems during human digestion. They resist being broken down in the gut and are stable in acidic environments, features that protect lectin-containing plants in nature.

When consumed, lectins in their active state can cause negative side effects. They contain phytohaemagglutinin, a type of lectin that can cause red blood cells to clump together. It can also produce nausea, vomiting, stomach upset, and diarrhea. Milder side effects include bloating and gas.

Certain lectins are toxic and cause harm when consumed in excess. Animal and cell studies have found that active lectins can interfere with the absorption of some minerals, such as calcium, iron, phosphorus, and zinc. Legumes and cereals often contain these minerals, so the concurrent presence of lectins may prevent the absorption and use of these minerals in the body.

Lectins can also bind to cells lining the digestive tract. This may disrupt the breakdown and absorption of nutrients and affect the growth and action of intestinal flora. Because lectin proteins bind to cells for long periods of time, they can potentially cause an autoimmune response and are theorized to play a role in inflammatory conditions like rheumatoid arthritis and type 1 diabetes.

Cooking, especially with wet high-heat methods like boiling or stewing, or soaking in water for several hours, can inactivate most lectins. Lectins are water-soluble and typically found on the outer surface of a food, so exposure to water removes them.

The body can produce enzymes during digestion that degrades some lectins. Other processes that deactivate the compounds are sprouting grains and beans, and mechanically removing the outer hull of beans and wheat grains that contain the most lectins.

Soaking legumes can help reduce lectin content. Make sure to change the water frequently. Adding baking soda to the soaking water will further neutralize lectins in beans.

Some natural lectin blockers include garlic, onion, ginger, and turmeric. These foods contain compounds that can help block lectins from binding to your cells.

Soaking Removes Contaminants

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.

Soaking Reduces Phytic Acid

Soaking reduces phytic acid effects. 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. Soaking legumes may reduce the effects of phytic acid on mineral absorption.

Soaking Reduces Anti-nutritional Enzyme Inhibitors

Leguminous crops such as beans, peas, and lentils contain several anti-nutritional factors. These anti-nutrient factors bind to beneficial enzymes which decreases their activity. We can improve the availability of nutrients present in these foods by removing their anti-nutrient factors (which include trypsin and chymotrypsin inhibitors, proteolytic enzyme inhibitors, oligosaccharides, and lectins). Soaking helps discard anti-nutrient compounds in the soaking water.

Soaking Reduces Tannins

Tannins are one of several antinutritional factors present in dry beans and are located mainly in the seed coat. The tannin content of dry beans ranges from 0.0 to 2.0% depending on the bean species and color of the seed coat. Naturally occurring food legume tannins are reported to interact with proteins (both enzyme and nonenzyme proteins) to form tannin-protein complexes resulting in inactivation of digestive enzymes and protein insolubility.

Bean tannins decrease protein digestibility, either by inactivating digestive enzymes or by reducing the susceptibility of the substrate proteins after forming complexes with tannins and absorbed ionizable iron.

Iron deficiency remains a global health issue, and antinutritional factors, such as tannins, are often cited as contributors to the high prevalence of deficiency. Tannins precipitate proteins and affect the utilization of vitamins and minerals. Tannins may reduce iron absorption at meals, especially when consumed alongside iron-rich foods.

The antinutritional activity of bean tannins can be reduced by soaking, and cooking.