Milk is one of the most important foods. So the nature is arranged that from the first day of life newborn children and young mammals feed only on mother's milk. It contains all the necessary substances for the normal functioning of the growing organism. But even as he grows older, a person does not refuse milk. We use it both in its natural form and in the processed one (fermented baked milk, yoghurts, cream, sour cream, cottage cheese, butter). There is whole and skim milk , fresh and baked, condensed and ... dry. And if with sour-milk products everything is more or less clear, the latter two are of great interest, especially in children. Surely a little fidget pestering you with a question: "What is milk made of?" In this article we will try to find an answer to it and learn a lot about a product familiar from childhood.
What milk is made of
Of course, if you think about it, then the question “what milk is made of” seems silly. But it only seems. Of course, we are not talking about natural products. Another thing is purchased milk. What are they made of? You can hear a similar question from the mouth of the city kid quite often, and there is no need to be surprised. In fact, this is the same cow's milk, it just goes through processing before it gets to our table. Some unscrupulous manufacturers may dilute it with water or add vegetable fats to increase its fat content. But this is extremely rare. Most of the milk is made from natural raw materials.
Composition
It should be noted that people are accustomed to eating not only cow's milk - in some regions they get it from female deer, goats, mares, buffaloes, and camels. The chemical composition of these products naturally varies. We will focus on the cow, because most often it is present on our table. So, it includes about 85% water, 3% protein (called casein), milk fat - up to 4.5%, up to 5.5% milk sugar (lactose), as well as vitamins and minerals. In factories and dairies where milk is made (or rather, processed), much attention is paid to fat content and protein content. With high fat content of the initial product, the yield of butter is greater, and protein is important in the manufacture of cottage cheese and various cheeses.
How to make milk at the factory and dairy factories
On the shelves of numerous stores you can always find milk. But before you get there, it goes through processing. It is needed in order to secure the product. Of course, useful properties are lost, but some still remain. Consider these processes in order. The raw milk supplied to the plant is first cooled, then homogenized. Homogenization is necessary so that when pouring milk into bags on the surface, cream does not settle. In fact, this is milk fat, which in the homogenizer is broken into small balls, evenly distributed over the entire mass of milk. This allows you to improve the taste of the original product, increases its digestibility. This is followed by heat treatment (it is necessary for the disinfection of milk, since it can be found not only beneficial microorganisms, but also pathogens) - this may be pasteurization, ultra-pasteurization or sterilization.
Types of heat treatment
The most common is the first method. It is the most gentle and allows you to preserve not only the taste and smell, but also useful properties. In addition, after pasteurization, milk is stored longer than usual. In modern industry, ultra-pasteurization has increasingly been used. This method differs from the previous one using ultrahigh temperature. Of course, there are no useful properties left at all. Sterilization is also characterized by heat treatment. Such milk is stored the longest (up to 6 months or even up to a year). As a rule, after heat treatment, bottling in plastic or plastic containers and sales through retail chains should be followed.
About milk powder
In addition to regular milk, there is also dry milk. Probably not all of us know how to make milk powder. For the first time this product became known back in 1832, when the Russian chemist M. Dirchov founded its production. In fact, to the question: “What is milk powder made of?” The answer is simple: from natural cow. The process consists of 2 stages. At first, the milk is subjected to thickening in high-pressure apparatuses. Next, the resulting mixture is dried in special devices. As a result, there remains a white powder - this is milk powder, or rather its dry residue, which has lost 85% of its volume (water). The only advantage of such a product over whole milk is the possibility of its long-term storage. Plus, it takes up little space, which is very important during transportation. The composition of milk powder is the same as that of whole milk, it just does not have water. What milk powder is made of is now clear. Let's move on to the field of its application.
Where is milk powder used?
How milk powder is made, we found out, now we will consider where it is used. Most often it is common in those regions where there is no possibility of obtaining a whole natural product. The powder is simply dissolved in warm water (in a ratio of 1 to 3), and then it is already used as intended. Also, milk powder is the basis for the production of baby food (dry milk porridge) and feed for small calves. The product can be found on free sale.
About baked milk
There is another type of this product indispensable for humans - baked milk. Many of us are probably wondering how to make baked milk. Its difference from the whole is the pronounced taste of pasteurization and the presence of a cream shade. The process presents the following picture: whole milk is mixed with cream to obtain a mass fraction of fat in raw materials of 4 or 6% (this process is called normalization). Then the mixture is subjected to homogenization (this process is mentioned above) and pasteurization with a long exposure (about 4 hours at a temperature of 95-99 º). In this case, the raw materials are periodically mixed so that a film of proteins and fat does not form on its surface. It is the long-term effect of temperature that contributes to the appearance of a cream color (milk sugar actively interacts with amino acids, as a result, melanoidin is formed, giving such a shade). The final stage is the cooling and bottling of baked milk in containers. That’s all wisdom. It should also be noted that fermented baked milk and katyk are produced from ghee (this is the name of this type among the people) (they are prepared using various starter cultures, which results in a fermented milk product with a thick consistency and taste of baked milk).
About skim milk
Very often in the dairy departments of stores you can find a package that says "Skim milk." What it is? In fact, this is ordinary milk, just without fat, that is, without cream. As a rule, the percentage of fat here is not more than 0.5%. And how do skim milk? Get it by separating the whole product in special devices - separators. There is a separation of cream from milk under the influence of centrifugal forces. The result is a skimmed liquid.
Scope of skim milk
The milk package always indicates the exact amount of fat and protein in the product. It should be noted that it is impossible to get milk with a specific fat content from a cow. This indicator is not the same even for one cow in different seasons. Since GOSTs have their own standards and requirements, milk has to be normalized with non-fat, in order to get the necessary fat content (2.5%, 3.2% or 6%). Also, such milk is used for the production of low-fat kefir, cottage cheese or yogurt. You can buy it in packaged form in any store. It costs, of course, cheaper than usual.
You can talk about milk and its benefits indefinitely. Not without reason have we always been told from childhood: “Drink milk - it is very healthy.” And this is true, our life begins with it - immediately after the birth of the baby they must be applied to the chest so that he receives the first portion of nutritious colostrum. Thanks to mother's milk, the baby's immunity is strengthened, the baby grows and develops. Surprisingly, in the first months of life, it fully meets the child's needs for water, nutrients, vitamins and minerals. Surely any of us noticed that dairy and sour-milk products always underlie healthy and proper nutrition. Curd is very useful for growing babies, it contains a lot of calcium, which is necessary for the growth of bones and healthy teeth. Doctors also recommend that older people include milk in their diet, as bones rapidly lose calcium during this period of life. Like it or not, this product is indispensable. In this article, we examined what milk is made of, what types of milk exist and how it is useful. Surely you learned a lot of new and interesting things for yourself. Be healthy!