This product is familiar to every inhabitant of our planet. Traditionally, milk is used as food by children and adults. Scientists scare us with arguments about its harmful properties, but this product has fewer fans.
This is due to the fact that milk is a natural product unique in composition and properties. In addition, these are raw materials for the production of a huge amount of food products, which we eat with great pleasure and health benefits. Let's take a closer look at cow's milk, composition and its beneficial properties in this article.
Is milk almost 90% water?
For many, this fact is surprising, but milk is indeed 87.5% water. All other amazing and useful components are concentrated in 12.5% solids.
This was determined by standard drying the milk sample to a constant weight at a temperature of 105 ° C. As a result of this process, the water is completely evaporated, and only
dry matter remains
.But the liquid consistency of milk is caused not by a large amount of water, but by the fact that all substances and compounds are in a dissolved state.
Milk is also characterized by the SOMO indicator (dry skim milk residue). This value is obtained if all water and fat are removed from milk. This indicator is normally at least 9% and serves as an indicator of the quality of a natural product. Cow's milk, the composition of which was depleted in dilution with water, will give the SOMO indicator much lower than the norm.
Is milk fat good for you?
The average milk fat content in cow's milk is 3.5%. This indicator is strictly controlled by farmers and receivers of raw materials in factories. It is this characteristic that affects the quality of products: sour cream, cream, cottage cheese.
Milk fat contains about 20 fatty acids. It is characterized by a low melting point (25-30 ° C) and solidification (17-28 ° C). A feature of this fat is its small drop-shaped structure in the composition of milk.
This leads to its high percentage (about 95%) of assimilation by the human body.
Due to its low specific gravity, milk fat rises to the surface with the formation of a layer of cream. This valuable product is loved by many, and contains a lot of useful fat-soluble vitamins: D, A, K, and E. Therefore, eating milk with a natural level of fat enriches the body with biologically active substances and has a beneficial effect on human health.
What is the peculiarity of milk proteins?
Cow's milk, which contains 3.2% protein, is considered a valuable nutritious product. This indicator is strictly monitored by both farmers and enterprises in the industry.
Milk protein is perfectly absorbed by the human body - more than 95%. Its peculiarity is in the content of essential amino acids, the deficiency of which leads to a violation of metabolic processes. These include the following:
- Methionine - metabolizes fats, preventing liver dystrophy.
- Tryptophan is the starting material for the synthesis of serotonin and nicotinic acid. Its deficiency can lead to dementia, diabetes, tuberculosis and cancer.
- Lysine contributes to normal blood formation. Its deficiency is capable of provoking anemia, metabolic disorders of nitrogenous substances and bone calcification, muscular dystrophy, and malfunction of the liver and lungs.
Basically, milk protein consists of casein. It is presented in two forms: the alpha form causes allergies in some people, the beta form is perceived by a person well.
Whey or sulfamide proteins, the content of which in milk is 0.6%, are a valuable nutrient and are widely used in the food industry.
In milk, there is microflora from the smallest organisms, which in the process of life emit special protein substances - enzymes, or enzymes. These structures regulate chemical processes in the product and the action of each of them is strictly specific. The activity of enzymes depends on the pH and temperature of the medium. Some of them help evaluate the quality of milk:
- Lipase promotes the breakdown of fats into free fatty acids and glycerol. This changes the taste of milk for the worse, reducing its quality. The abundance of free fatty acids and their oxidation leads to rancidity of the product.
- Peroxidase , a thermoactive enzyme, serves as an indicator that milk is pasteurized at 80 ° C.
- Catalase breaks down hydrogen peroxide to water and oxygen. In milk from sick cows, the level of catalase is quite high.
- Phosphatase breaks down esters to phosphoric acid and alcohols and is destroyed by conventional pasteurization. Its absence serves as confirmation of the normal pasteurization.
Milk sugar and its transformations
The chemical composition of cow's milk includes a special compound - lactose, or milk sugar.
For the human body, this component serves as an energy source.
The lactase enzyme breaks down lactose to glucose and galactose.
Milk sugar helps suppress the activity of pathogenic putrefactive microflora. Lactose has a beneficial effect on the nervous and cardiovascular activities of the human body.
Some people have a problem of rejection of milk sugar, called lactase deficiency. This disease can be congenital or develops over the years. The cause may be a past illness of the digestive tract or prolonged abstinence from drinking milk.
Microorganisms produce, as already mentioned, a special enzyme - lactase, which breaks down milk sugar with the formation of simpler compounds: glucose and galactose. The first of these substances is a favorite food for most bacteria. Further, this is what happens with glucose, which is part of cow's milk: microorganisms ferment it, releasing lactic acid, alcohol and carbon dioxide. As a result of this transformation, a weakly acidic environment is created in the human intestines, which has a beneficial effect on the development of beneficial acidophilic microflora. The activity of rotting bacteria is suppressed.
Mineral substances of milk
Cow's milk, which includes organic and mineral components, is a source of valuable nutrients for the human body. Its peculiarity is that the mutual action of substances leads to their best assimilation. The following macronutrients can be distinguished in the composition of milk:
- Calcium - is present in an easily digestible form and in balance with phosphorus. It is in the form of ions (10%), in the form of phosphates and citrates (68%), in combination with casein (22%). The total content of this element in milk is 100-140 mg, and in summer this indicator is lower.
- Phosphorus , the content of which ranges from 74-130 mg, is present in two forms. It is part of inorganic compounds in the form of calcium phosphates and other metals. Phosphorus is also included in organic substances - esters, casein, phospholipids, enzymes, nucleic acids.
- Magnesium , the content of which is in the range of 12-14 mg, has a beneficial effect on the nervous, digestive and reproductive function of a person, increases immunity.
- Potassium (135-170 mg) and sodium (30-77 mg) support osmosis and buffering of all body fluids. They increase the solubility of many mineral compounds and acids, casein micelles;
- Chlorine (90-120 mg) is an indicator of the health of the animal. A 30% increase in concentration indicates mastitis in the cow.
The composition of milk also contains a large number of trace elements. Despite the fact that their content is very small, these substances have a huge impact on the normal functioning of the human body. Milk contains iron, copper, zinc, manganese, iodine, molybdenum, fluorine, aluminum, silicon, selenium, tin, chromium, and lead. All of them provide a physiological course of processes in the human body.
Milk composition table
The indicators of the constituent components of milk may vary. These data are influenced by the breed of cows, the quality of feed, season, and much more. But the average composition of cow's milk, the table of which is given below, is reduced to the following indicators:
Composition of Cow's Milk| Component Name | Content Limits | Average |
| Water | 85.0 - 90.0 | 87.8 |
| Dry residue | 10.0 - 15.0 | 12,2 |
| Squirrels | 2.8 - 3.6 | 3.2 |
| Casein | 2.2 - 3.0 | 2.6 |
| Albumen | 0.2 - 0.6 | 0.45 |
| Globulin | 0.05 - 0.15 | 0.1 |
| Other proteins | 0.05 - 0.2 | 0.1 |
| Lactose | 4.0 - 5.3 | 4.8 |
| Fats | 2.7 - 6.0 | 3,5 |
| Triglycerides | | 3,5 |
| Phospholipids | | 0,03 |
| Cholesterol | | 0.01 |
| Mineral components | | 0.7 |
| Lemon acid | | 0.16 |
| Enzymes | | 0,025 |
Useful and harmful microcomponents of milk
Whole cow's milk also contains vitamins, enzymes and pigments. Their content is measured in hundredths and thousandths of a percent, but the value of these substances is very high. They have great biological activity, and even their very small presence is important for the human body.
Currently, about 50 vitamins are found in milk, among which there are water-soluble - B1, B2, C - and fat-soluble - A, D, E, K. The presence of these biologically active components determines the health benefits of milk, as their effect on physiology hard to overestimate.
But the composition of this product may also include substances that can harm the body. Their content is also very small, but even these small doses can cause great harm to human health. These include:
- Toxic elements: arsenic (not higher than 0.05 mg / kg), lead (not higher than 0.1 mg / kg), mercury (0.005 mg / kg), cadmium (0.03 mg / kg).
They can be found in milk along with feed or packaging. Their number is strictly standardized and controlled.
- Mycotoxins, in particular aflatoxin M1, are highly toxic products of molds with a pronounced carcinogenic effect. It enters milk with food, is not eliminated by pasteurization. Its content is strictly normalized to 0.0005 mg / l.
- Antibiotics - tetracyclines, penicillins, chloramphenicol, streptomycin.
- Inhibitors - soda and other detergents and disinfectants.
- Pesticides and radionuclides (strontium-90, cesium-137) - together with feed.
- Hormones in the form of estrogen are found in fresh milk. Therefore, in order to avoid hormonal disorders, this type of product is not recommended for children.
- Various pathogenic and conditionally pathogenic microorganisms.
Thus, cow's milk, the composition and properties of which directly depend on nutrition and animal welfare conditions, can bring not only benefits, but also harm. When buying this product, you should trust industrial companies that have established themselves in the market. As a rule, such milk undergoes laboratory tests at all stages of the technological process, and the content of all useful and harmful substances in it is strictly controlled. A product purchased from a private trader on a spontaneous market is a mystery, both for the seller and the buyer. Do not risk your own health, succumbing to the tempting call to buy "real homemade milk."
What is remarkable goat milk?
Some people currently prefer goat milk.
They explain this by the presence of obvious advantages in the product. The composition of goat and cow milk is really slightly different. Here are some facts confirming the difference between these two products:
- The cobalt content in goat's milk is 6 times higher than that in cow's product.
- Alpha-1S-casein is practically absent in goat milk, which gives it the status of a hypoallergenic product.
- The lactose content in goat’s milk is 53% less than in cow’s milk. This fact makes it easy for people with lactose deficiency to absorb.
- Goat milk has a fat content of 4.4%, with 69% of the acids being polyunsaturated and fighting cholesterol.
- Goat milk has far fewer pathogens.
Which milk is better?
Which milk to eat - cow or goat - is up to you. Both products are worthy of respect and are rightfully considered valuable and healthy. The main thing is to remember safety and not to buy goods of dubious quality. Resist the temptation to try fresh milk from the market. It can have many pathogenic bacteria and toxic substances. It’s best to buy the proper control and certification. Thus, you can protect yourself and your family from the threat that it is simply impossible to evaluate with the naked eye. Drink quality milk with pleasure!