Protein types by origin
All proteins are evaluated relative to the whole egg protein of chicken, which is considered the reference and is easily absorbed by the body. Protein eggs of chicken – this is almost 100% albumin (ovalbumin). The yolk includes seven protein compounds: lysozin, avidin, ovomucoid, ovomycin, ovoglobulin, coalbumin and albumin.
However, such a variety of protein compounds, which contains a chicken egg, requires the rational use of this unique product in food. Specialists do not recommend the inclusion in the diet of a large number of raw eggs, as they contain an inhibitor of the enzyme trypsin, slowing down the digestive process. Avidin, contained in the yolk protein, in conjunction with the important biotin (vitamin H) in the body, forms a substance that does not lend itself to digestion and does not digest the body. Chicken egg is recommended for eating after cooking. In the process of cooking, already at 70 ° C, the trypsin inhibitor is destroyed, and at 80 ° C, the active biotin is released from the biotin-avidin complex.
Studies on the effect of egg protein on the human body were conducted by scientists from Taiwan and Japan. For this study, three groups of women were selected who wish to participate in this experiment. Women were practically healthy, but they had high cholesterol in their blood. The experiment participants fed on dietary food, the energy value of which did not exceed 1750 calories per day, and was taken daily by 70 g protein. 20% of the protein, from the total number of calories, they received in the form of fats. Participants in the first group of the 30% protein experiment received egg white, the second group received protein from cheese, and women from the third group from soy cheese. During the experiment, the weight of the subjects and their physical loads did not change. At the end of the study, it was found that the women who received protein from soy cheese and egg protein, the cholesterol level in the blood became lower, and the number of useful lipoproteins increased. In women taking protein in the form of cheese, the cholesterol content in the blood increased. The results of the experiment confirm the positive effect of egg protein on the human body.
Together with this, scientists were interested in what effect the whole egg has on the body. In 1996, the publication of the Annals of Nutrition and Metabolism published the results of a study that showed that in a group of subjects who consumed whole eggs during the day, the level of useful cholesterol (high-density lipoproteins) decreased. This in itself prevents the development of atherosclerosis in a person.
Nevertheless, the use of whole eggs in food is not always so useful, because the presence in them of a large amount of polyunsaturated fat causes in the body increased oxidation. As is known, polyunsaturated fats, including Omega-3 fats, which contain fish and linseed oil, are especially prone to oxidation. However, this process can be prevented by eating the so-called antioxidants: selenium and beta-carotene, vitamins C, E, PP. They inhibit oxidation and form the process of stabilization of polyunsaturated fats.
Cholesterol is found in cell membranes. In a young organism, its deficiency leads to a multitude of problems, including a delay in physical development. Do not have problems with an increased amount of cholesterol in the blood of 90% of bodybuilders before the age of 30 years. This means that they are excluded from the formation of pathology in fat metabolism, which manifests itself in the form of hypercholesterolemia. Bodybuilding is aimed at increasing the amount of muscle mass, so in bodybuilding organisms, cholesterol is used in significant amounts. Bodybuilders consume vitamins A, C and E, which, being antioxidants, ensure the harmlessness of whole eggs. The amount of fats contained in the egg is small, and will not affect the growth of muscle mass. In addition, egg yolks contain useful microelements, bioactive substances and vitamins.
Thus, it can be said with certainty that eating whole eggs is especially useful when recruiting muscle mass. With a decrease in body weight in the diet, it is necessary to include only protein, giving up the yolk. Whole egg white eggs and egg albumin are used to make food additives for athletes. Such sports nutrition is considered the most qualitative and effective, because it contains all useful substances and eliminates all possible shortcomings that have whole eggs. Since the process of assimilation of egg white is somewhat slowed down, it makes it possible to include it in the diet with a decrease in body weight without fear of slowing down weight loss.
- rapid absorption makes its use appropriate only before and after training, and during the day only in combination with other proteins
- is slowly absorbed, which allows maintaining a high concentration of amino acids in the blood during the day
The main serum proteins are lactoglobulin, lactalbumin, and immunoglobulin. Whey proteins have the highest digestibility among whole proteins in the human body, since they are the fastest cleaved. Already within an hour after the consumption of whey proteins, the concentration of peptides and amino acids in the blood increases. In this case, the acid-forming function of the stomach does not change, which excludes the formation of gases and disruption of the gastrointestinal tract. About 14% of whey proteins are hydrolysates of amino acids, di-, tri- and polypeptides. With their help, the process of digestion, the synthesis of many important hormones and enzymes, the reduction of cholesterol in the blood.
Amino acid compositions of human serum proteins and muscle tissue are almost identical. The essential amino acids and branched chain amino acids (leucine, isoleucine and valine) contained in whey proteins are superior in their number to other animals and plant proteins.
Canadian scientist Gustavo Bownos and his colleagues from McGill University have proved that whey protein is the most effective accelerator of cellular and hormonal reactions. The immunostimulating effect of whey protein is associated with its rich content of essential amino acids. In addition, whey protein is able to increase the body's level of one of the most important antioxidants – glutathione. Whey protein, in its function of providing athletes with protein, significantly exceeds other types of proteins – egg, vegetable, soybean and fish. In the course of the experiments it was found that the optimal whey protein content in special food additives equals 60-65%. Increasing the protein content requires the introduction of additional vitamin-mineral formulas into the mixture.
Sweet whey, which is obtained by the production of rennet cheese, is the main source of whey proteins. But due to the presence of a large amount of milk sugar (lactose), which sometimes causes intolerance to dairy products, and a low protein content in it, sweet whey is not used in its pure form to produce food protein supplements.
Concentrate is the first among the extracted forms of whey protein. Serum is passed through incredibly tiny holes in the ceramic membrane. The fat molecules and lactose carbohydrates freely pass through these holes, while the remaining protein fractions, which are much larger, are retained. The difficulty lies in the fact that technical capabilities do not allow making holes of the same size, therefore this type of filtration can not be considered absolutely clean. The heterogeneous mass settling on this kind of filter contains from 35% to 85% of the protein. Fats and lactose, which it contains, can cause increased gas production. For this reason, concentrate is the cheapest form of whey protein among other sports nutrition products. Concentrate can be considered an alternative option solely because of insufficient financial capacity.
Whey Protein Isolate is a substance that is much cleaner than concentrate. To obtain the isolate, the method of long-term filtration or ion exchange is used. In the end result, the manufacturer has a dry mass, which contains more than 95% of protein fractions. Lactose and fats in the isolate are almost absent, which indicates its ideal for the purpose of compensating for the deficiency of amino acids both before and after training. The indisputable advantage of the isolate is its cheapness compared with the hydrolyzate, and is therefore more accessible to the general population. There are manufacturers who go on tricks and sell a "cocktail" of three kinds of protein (concentrate, isolate, hydrolyzate), giving it for whey protein. Therefore, the amount of inexpensive concentrate in such products is very high and reaches 60-70%. Naturally, it is better to choose the additives, in which the isolate is the main constituent or the only ingredient.
Whey Protein Hydrolyzate is the most expensive protein. It is high cost that is the main disadvantage of this type of whey protein, so its permanent use can only be afforded by wealthy people. This kind of protein is obtained by hydrolysis, during which large protein molecules are broken down into separate fractions. Due to this, the protein is instantly absorbed and almost immediately penetrates into the muscles.
However, not all whey protein hydrolysates are qualitative. Nowadays, there are many kinds of hydrolysis equipment, which does not always strictly observe the technology of protein production, which worsens its quality, and allows the manufacturer to save significantly. Experts believe that there are many kinds of hydrolysates containing not more than 50% of cut protein fractions.
The products of sports and medical nutrition in the modern market are represented by various forms of protein-containing products. First of all, it's protein soups and cocktails with different flavors. They can be sold both in finished form and in powders that require preparation. Sweets are equally popular: chocolate, nut halva, energy bars, protein pastes, biscuits, etc. Such products need to be bought in pharmacies or specialized stores.
In addition to the sports protein, the mixtures of amino acids required for its assimilation are offered. They are produced in the form of powders, liquids and even injectable solutions. Along with amino acids, products containing a complex of several components for different purposes are offered. Such amino acid complexes are most quickly absorbed by the human body, since they are practically digested protein. For example, BCAA amino acids that enhance muscle metabolism, a mixture of L-arginine, L-ornithine, and L-lysine, stimulating the secretion of growth hormone, amino acid L-glutamine, which protects muscle tissue during intense training, etc.
Modern ideas about nutrition consider the introduction of casein into children's mixtures biologically justified. The mechanism of action is as follows: casein, getting into the stomach, curdles and turns into a clot, digestion of which lasts long enough, in connection with which the rate of protein breakdown is reduced. Thus, amino acids enter the body stably and evenly, this is especially important for a child whose growth is intense. If such a rhythm of digestion is disturbed, say, due to the use of mixtures of whey protein in the base, then the growing organism of the child may not have time to absorb the rapid flow of amino acids, and this is fraught with various deviations in development. Therefore, the use of nutritional mixtures based on casein is highly recommended by nutritionists for infants. For an adult person, especially with significant physical exertion, low digestibility and slow passage of casein in the digestive tract are unacceptable. In view of this, it is obvious that caseinates (dietary supplements based on casein alone) are ineffective for adults.
Nevertheless, there is a compromise solution: protein compositions, which are based on casein and whey proteins. Optimum proportions of substances are selected depending on the maximum efficiency factor of the protein, determined by the relevant studies. The most acceptable was the proportion of 63: 37. This ratio gives the efficiency factor of the 3,49 protein. In this situation, the value of the biological value of the protein composition is rather high. Moreover, as one can draw from literature, this value is not inferior to the biological value of proteins of animal origin.
If you observe the digestibility, it gradually grows as the proportion of whey proteins increases. The data obtained during the study confirm a known fact: whey proteins are digested by digestive enzymes better than casein.
Soy protein is well balanced in amino acids, including indispensable. The main advantage of soy protein is that it is not of animal origin and it is excellent for people with intolerance to lactose. Soy protein contains such valuable ingredients as saponins and phytosterols. Saponins support the immune system and lower cholesterol. Phytosterols also maintain cholesterol levels within normal limits. From soy, the body receives vitamins necessary for vitality (E, all B vitamins) and minerals (potassium, phosphorus, iron, zinc). Soy is very useful for women's health – this product prevents the development of osteoporosis in old age, reduces the risk of developing breast cancers. For men, soy is also useful because it has a beneficial effect on the problem with prostatitis.
Food additives in their composition have soy flour (protein content 40-50%), soy concentrate (protein level 65-75%), and soy isolate (more than 85%). Whatever the ideal product may seem soy at first glance, it also has its drawbacks. Soy protein contains trypsin, an inhibitor of the digestive enzyme, which is a serious negative factor. The amount of trypsin can be different depending on the processing technology of soybeans. The inhibitor can be eliminated by further processing the protein by enzymatic hydrolysis. This procedure is carried out by pancreatin electrophoresis and takes fifty minutes. There is one more important point: soy protein can damage the walls of the small intestine. These negative factors influence the fact that the introduction of soy protein into food additives is very limited.
Soy protein has one negative property for male bodybuilders. Soy protein is rich in isoflavones and because of this, men need to beware of regular intake of soy proteins in large quantities. The fact is that regular use of soy protein significantly lowers testosterone levels. Studies have shown that daily intake of 32 g of soy protein for 29 days lowers testosterone levels by 10%. And after 57 days, the level of female hormones may exceed testosterone levels. On the other hand, it is believed that thanks to soy isoflavones, you can protect your body from cancer and cardiovascular diseases.
In addition, studies show that the use of soy for a long period causes hypothyroidism – a violation of the thyroid gland. What is particularly interesting, this problem is relevant for men, and women are not affected by this change.
From plant foods, you can get proteins that are themselves inadequate, but their combination is able to make a full protein. The combination of legumes and grains is especially effective, in it the content of a high-grade protein is greatest. It should also be remembered that soybeans, unlike other plants, contain a high-grade protein, not inferior to whey and egg – their value, expressed in PDCAAS, is the same.
The digestibility of vegetable protein can be quite low, which is caused by a number of reasons:
- plant cells have a thick shell, which often does not lend itself to digestion by digestive juices;
Earlier it was planned to use the fish protein isolate in the ration of athletes. Experiments that were conducted at the Institute of Food Hygiene in Kiev showed that, in comparison with casein, the isolate of fresh fish, is split to amino acids much longer. The isolate was cleaved to peptides more than 180 minutes after the protein was introduced.
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