Legumes are the seeds of plants known with the same name. Although there are many legumes, only a few are used in human consumption, highlighting chickpeas, beans, lentils, peanuts, soybeans, broad beans, peas, grass peas, alfalfa, lupins and carob beans.
Although they are usually eaten dehydrated - with few exceptions - they do not present nutritional differences with fresh ones except in the amount of water they contain. Legumes stand out for the amount of protein of plant origin that they contribute to our diet. The content in most seeds ranges from a minimum of 20% to a maximum of 38% in soybeans and peanuts. In fact, this richness in nitrogenous substances, which are ultimately proteins, have historically been used by humans to feed livestock and also to fix nitrogen in poor soils in which traditional crops alternated with legumes.
60% of the content of the seeds is in the form of carbohydrates, both complex such as starch or simple such as glucose, fructose, raffinose etc. They are also very rich in fiber so they are essential to prevent constipation or slow down digestion, something necessary in diabetics to avoid blood glucose peaks.
Legumes have good amounts of micronutrients, highlighting copper, iron, calcium as well as vitamin B1, B3 and B9. However, they practically lack vitamin C except when they are green.
As for proteins, they are easily assimilated but are usually deficient in the amino acid methionine, so they complement very well with cereals that do have it. In the same way, cereals are deficient in lysine, which in turn legumes do.
There is a belief that they generate gases. This is due to raffinose, an oligosaccharide that can ferment in the intestine, generating the annoying gases. The legumes most likely to produce gas are beans, soybeans and lima beans. The least are peas, lentils and chickpeas. However, these gases are produced either because they have not been prepared correctly before cooking or because the subject does not eat them often. When the intestinal flora gets used to legumes, gases disappear and their effect is very positive since they are slowly absorbed foods.
Regarding the preparation, you must bear in mind that while some products such as fish and meat give up water when cooked, others such as cereals and legumes gain it (they are hydrated). In addition, to cook dried legumes it is necessary to hydrate them for a minimum of 8 hours. With this operation they will gain water and it will be easier to cook them. Never soak legumes with bicarbonate because it kills vitamin B1. In principle, lentils, due to their small size, should not be soaked, although some types need it (check this in the recommendations of the package).
All the dried legumes are cooked starting from cold water. When the water begins to boil, the tumultuous cooking should be maintained with the casserole uncovered for about 10 or 15 minutes, after which the fire should be moderated following conventional cooking. With soybeans this period increases up to the hour. A good tactic for tenderizing legumes is what is popularly known as "scaring." By scare it is meant to stop the tumultuous cooking by pouring cold water. This technique is suitable for dried lentils and beans but should not be practiced on chickpeas as they will be stone hard. The cooking time varies with each type of legume and even with the different varieties of the same class. Generally it is 90 minutes for the small varieties and up to two hours for the larger ones. This time is substantially shortened by using a pressure cooker.
It is important to remove the foam, caused by impurities in the water and by the vegetables themselves, on a regular basis. Since the legumes must be hydrated, we have to anticipate the amount of water to add. In general, for a "dry" result, each unit of legumes will be boiled in three units of water (that is, a cup of legumes in three cups of water) while if a soup-like result is desired, the ratio is 1 to 5. All ALWAYS taking into account the previous 8-hour hydration.
Legumes constitute an excellent supply of proteins of vegetable origin, energy through carbohydrates and fiber, so they should be consumed between 2 and 3 times a week. Among them the most popular are lentils and chickpeas. Like any food that contains protein, its intake should be monitored since they can cause allergies (mainly lentils, peas, peanuts, soybeans and lupins) while the one that causes the least problems is the bean. If the individual is allergic, there may also be problems with additives obtained from legumes (thickeners and stabilizers) such as gum arabic, traganto, guar and locust bean, which may be present in any food product.