Legume protein

Legumes

Legumes, also called legumes, Fabaceae or Papilionaceae, are flowering plants of the Fabales order; legumes produce a fruit called pod of which the seeds enclosed inside are mainly edible.

Legumes are foods that boast extreme flexibility; they can be used as a first course, as a side dish, as a second course (if paired with cereals) ... and some of their flours can be used in the food additives sector (thickeners - such as carob seed flour E410) or as a substrate cutting (for example chickpea flour) to reduce the amount of wheat in food products.

Nutritional characteristics

Legumes represent a category of foods with numerous nutritional qualities; although some recent theories (???) have tried to discredit them, these seeds continue to demonstrate a very high therapeutic efficacy in a large part of the dysmetabolic pathologies with a SOVReduced aetiology; in simple terms:

teaching how to use legumes as a substitute for refined grains (in people who tend to exceed with food) determines: a significant reduction in excess calories, an increase in dietary fiber (with moderation of the global glycemic index and absorption fat), a reduction in cholesterol by lecithin) and circulating triglycerides, and an increase in the intake of vitamins and mineral salts.

Compared to refined grains and related farinaceous derivatives, legumes provide:

• More protein
• Less carbohydrates
• More dietary fiber
• More potassium (K)
• More iron (Fe)
• More calcium (Ca)
• More phosphorus (P)
• More thiamine (B1)
• More riboflavin (B2)
• More niacin (PP)
• They do not contain gluten!

Proteins contained in legumes

The legume proteins are said to have a medium biological value (medium VB) and are made from a minimum of 18% (some chickpeas) to a maximum of 44.3% (dry lupins).

The biological value is a qualitative evaluation parameter of food proteins based on the analysis of the essential amino acids contained in them; more precise, the VB is given by the similarity of composition between the examined protein and the human one. It is expressed with a numerical value in its turn referring to the protein nitrogen actually absorbed and used by the body, therefore net of urinary, fecal, cutaneous losses, etc. (see the article: "Protein quality"). The reference protein for the calculation of the biological value is that of the egg, which has a VB = 100 (it is estimated that out of 100g of amino acids 32, 256 g of essential aa and 67, 744 g of non-essential aa are identified).

NB . The biological value shown in the tables refers to raw foods; they, after cooking, have a significantly reduced VB.

It follows that: almost all dietary proteins (including legume proteins), compared to those of human tissues or raw eggs, are deficient in one or more essential amino acids. The specific deficiency level can be evaluated in percentage with a parameter known as index or chemical score (IC), that is: if in the human protein the "X" amino acid is present in quantity 10, while in the analyzed protein there are only 5 ... it is possible to define that the analyzed protein is 50% deficient in the "X" amino acid (IPC = 50%).

Biological Value (VB) :

• Eggs, milk and dairy products, meat and fishery products → contain ALTO VB proteins
• Legumes, nuts and cereal germs → contain MEDIUM VB proteins
• Refined cereals flour, vegetables, mushrooms and fruit → contain LOW VB proteins

Calculating the biological value can be very useful, especially in "special" diets such as veganism (potentially lacking in some essential amino acids), but also in assessing the sports contribution of the athlete; the latter, due to the fatigue induced by physical exercise, tends to require a greater protein intake and in particular 3 amino acids called branched (leucine, isoleucine and valine). The branched amino acids are particularly subject to combustion as they do not require the commitment of the liver (deamination and transamination) for the production of energy; therefore, in the sportsman's diet food proteins will NEVER have to be deficient in branched aa.

The legume proteins are deficient ESPECIALLY in methionine and cysteine, while lysine (4 - 5.5%) and tryptophan (both deficient in cereals) are more than sufficient. By combining legume proteins with cereals, it is therefore possible to reach a total biological VB equal to that of animal proteins.

NB . Another method to improve the VB of cereal proteins is to integrate them with a few similar animal-type molecules, which contain up to 7% lysine.

Comparing the biological value of some legumes and cereals:

... with that of some foods of animal origin ....

it is clear that the actual difference can be easily bridged through a food association between legume and cereal proteins.

Furthermore, observing the table below (percentage content in essential amino acids of some foods) it is also possible to deduce that: by combining cereals with legumes it is possible to easily reach a biological value almost similar to that of the egg .

Bibliography:

• Cereals and legumes in the diet for health - A. Formenti, C. Mazzi - Tecniche Nuove - pag 46-49