Cow's milk: composition and properties. Composition of cow's milk - table

2024 Author: Isabella Gilson | [email protected]. Last modified: 2023-12-17 03:14

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 does not become less fans.

This is due to the fact that milk is a natural product that is unique in composition and properties. In addition, it is a raw material for the production of a huge number of food products that we consume with great pleasure and he alth benefits. Let's take a closer look at cow's milk, its composition and its beneficial properties in this article.

Milk is almost 90% water?

For many, this fact is surprising, but milk is really 87.5% water. All other amazing and useful components are concentrated in 12.5% of solids.

This was determined by standard drying a milk sample toconstant weight at a temperature of 105 ˚С. As a result of this process, the water is completely evaporated, and only dry substances remain.

But the liquid consistency of milk is not due to a large amount of water, but to the fact that all substances and compounds are in a dissolved state.

Milk is also characterized by SOMO (dry skimmed milk residue). This value is obtained when 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 has been depleted by dilution with water, will give a SOMO value much lower than the standard.

Is milk fat good?

The level of milk fat in cow's milk averages 3.5%. This indicator is strictly controlled by farmers and raw material inspectors at 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˚С) and solidification (17-28˚С). The peculiarity of this fat is its small teardrop-shaped structure in the composition of milk.

This causes its high percentage (about 95%) absorption by the human body.

Due to its low specific gravity, milk fat rises to the surface to form 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 withnatural level of fat enriches the body with biologically active substances and has a beneficial effect on human he alth.

What is special about milk proteins?

Cow's milk, whose composition includes proteins in the amount of 3.2%, is considered a valuable nutritious product. This indicator is strictly monitored by both farmers and enterprises of the relevant 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 disruption of metabolic processes. These include the following:

• Methionine - exchanges 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 promotes normal hematopoiesis. Its deficiency can provoke anemia, metabolic disorders of nitrogenous substances and bone calcification, muscular dystrophy, malfunction of the liver and lungs.

Mostly milk protein consists of casein. It is presented in two forms: the alpha variety causes allergies in some people, the beta form is well received by humans.

Whey or sulfamide proteins, at 0.6% in milk, are a valuable nutrient and are widely used in the food industry.

In milk there is a microflora of the smallest organisms, which, in the process of life, secrete specialprotein substances - enzymes, or enzymes. These structures regulate the chemical processes in the product and the action of each of them is strictly specific. Enzyme activity 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, indicates that milk has been pasteurized at 80˚C.
• Catalase breaks down hydrogen peroxide into 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 confirms that pasteurization has been carried out normally.

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 into glucose and galactose.

Milk sugar helps to suppress the activity of pathogenic putrefactive microflora. Lactose has a beneficial effect on the nervous and cardiovascular activity of the human body.

Some people have a problem with milk sugar aversion called lactase deficiency. This disease may be congenital ordevelops over the years. The cause may be a previous disease of the digestive tract or prolonged abstinence from drinking milk.

Microorganisms produce, as already mentioned, a special enzyme - lactase, which breaks down milk sugar to form simpler compounds: glucose and galactose. The first of the obtained substances is a favorite food for most bacteria. Next, here's what happens to the glucose that is part of cow's milk: microorganisms ferment it, releasing lactic acid, alcohol and carbon dioxide. As a result of this transformation, a slightly acidic environment is created in the human intestine, which has a beneficial effect on the development of beneficial acidophilic microflora. The activity of decay bacteria is suppressed.

Milk minerals

Cow's milk, the composition of 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 - 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 figure 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 matter -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 functions of a person, improves immunity.
• Potassium (135-170 mg) and sodium (30-77 mg) support osmosis and buffering of all fluids in the human body. They increase the solubility of many mineral compounds and acids, casein micelles;
• Chlorine (90-120mg) is an indicator of the animal's he alth. An increase in its concentration by 30% indicates the presence of mastitis in a cow.

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, lead. All of them provide the physiological course of processes in the human body.

Milk composition table

Indicators of the constituent components of milk may vary. These data are influenced by the breed of cows, the quality of feed, the time of year, and much more. But the average composition of cow's milk, the table of which is given below, comes down 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
Proteins	2, 8 - 3, 6	3, 2
Casein	2, 2 - 3, 0	2, 6
Albumin	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
Citric 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 a very small presence of them is important for the human body.

Currently, about 50 vitamins have been 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 benefits of milk for human he alth, so how their influence on physiology is difficult to overestimate.

But the composition of this productmay include substances that can harm the body. Their content is also very small, but even these small doses can cause great damage to human he alth. These include:

Toxic elements: arsenic (0.05mg/kg max), lead (0.1mg/kg max), mercury (0.005mg/kg), cadmium (0.03mg/kg)

They can get into the milk along with feed or containers. Their number is strictly regulated and controlled.

• Mycotoxins, in particular aflatoxin M1, are highly toxic fungal products with a pronounced carcinogenic effect. Gets into milk along with feed, is not eliminated by pasteurization. Its content is strictly regulated within 0.0005 mg/l.
• Antibiotics - tetracyclines, penicillins, chloramphenicol, streptomycin.
• Inhibitors - soda and other detergents and disinfectants.
• Pesticides and radionuclides (strontium-90, cesium-137) - along 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 opportunistic pathogens.

Thus, cow's milk, the composition and properties of which directly depend on the nutrition and conditions of animals, can bring not only benefits, but also harm. When buying this product, you should trust industrial companies that have proven themselves in the market. As a rule, such milk undergoes laboratory tests at all stages of the technological process, andThe content of all useful and harmful substances in it is strictly controlled. A product bought from a private trader on a spontaneous market is a mystery, both for the seller and for the buyer. It is not worth risking your own he alth by falling for the tempting call to buy “real homemade milk.”

What's special about goat's milk?

Some people now prefer goat milk.

They explain this by the fact that the product has obvious advantages. The composition of goat's and cow's milk is indeed somewhat different. Here are some facts that confirm the difference between these two products:

• The content of cob alt in goat's milk is 6 times higher than in cow's milk.
• Goat milk is virtually free of alpha-1S-casein, making it hypoallergenic.
• The content of lactose in goat's milk is less than in cow's milk by 53%. This fact makes it easy for people with lactose intolerance to digest.
• The fat content of goat milk is 4.4%, and 69% of acids are polyunsaturated and fight cholesterol.
• Goat milk has far fewer pathogens.

Which milk is best?

What kind of milk to eat - cow's or goat's - you decide. Both products are worthy of respect and are rightfully considered valuable and beneficial to he alth. The main thing is to remember about safety and not to buy goods of dubious quality. Resist the temptation to try fresh milk from the market. It may contain manypathogenic bacteria and toxic substances. It is best to buy the past due control and certification. Thus, you can protect yourself and your family from the threat that is simply impossible to assess with the naked eye. Drink quality milk with pleasure!