The acidity of milk: what is it, how to determine what it depends on

Cow's milk is one of the most useful products for both adults and children. It contains a huge number of components that our body needs. And such components as protein, sugar and fat are best absorbed in the human body. The higher the protein level in milk, the more it is valued. Therefore, increasing the level of protein is a very important and time-consuming work. In developed countries, half the cost of this product depends directly on the protein content in it. To do this, producers of milk and dairy products make sure that the cows are kept in good conditions and receive food rich in vitamins.

It is also very important to control the acidity, as in the case of the souring of the product, it is already becoming unfit for sale to consumers.

What determines the acidity of milk?

The chemical composition of milk depends on many factors. It affects the conditions of the animal, its physiological state and other. The process of forming milk is quite complex, in which the state of the animal's living environment is important. On its formation and secretion, on average, 10% of all nutrients that enter the mammary gland with blood are expended. So, to get one liter of cow's milk, it is necessary that about 500 liters of blood pass through the mammary gland. Its properties change constantly, from the moment of milking until it reaches the final consumer. Milk is very different in composition. So, in colostrum, twenty percent of the protein is more than in the coliform, which makes it much more useful. Such milk in its composition contains a large number of useful substances and minerals. Also, the colostrum contains a minimal amount of fermented microorganisms, which allows it to remain as fresh as possible.

Degree of acidity

In the process of storage of milk under the influence of sour-milk microorganisms, which develop in it, lactose decomposes, due to the formation of lactic acid and acidity. Its level is expressed in degrees according to Turner (T).

Freshly baked milk has a degree of acidity of 16-18 T. But in addition to these indicators, buffering is an important characteristic. In milk there are components, due to which the pH does not change with the addition of acids and alkalis. The higher the buffer properties, the more reagents are required to change the pH. Similarly, the increased acidity of milk is observed in those cows that graze in summer in meadows or fields where cereal crops grow. This is due to the fact that in the composition of meadow grasses and cereals a lower level of calcium. Scientists have long established a relationship between the content of calcium in milk and sour-milk microorganisms. It was found that the less calcium in milk, the higher its acidity. Accordingly, with an increase in the calcium content in food, the acidity index decreases.

The device for measuring acidity

To determine the acidity of milk, farmers and other manufacturers use a specially developed device called the pH meter. This device initially measures the EMF (electromotive force) of the electronic system. After this, the temperature of the dairy product is further measured. At the same time, the pH value, which is reduced to 20 degrees, is determined by a specially derived formula.

PH meter for measuring acidity refers to the dairy and food industries. It can be used to measure the active acidity of milk and dairy products.

This method of determining the acidity of milk to date is considered the most accurate.

Effect of pH meter

In order to determine the level of acid microorganisms in milk, the sensors of the device are immersed in it or any other dairy product, which contains a measuring temperature electrode and a silver chloride reference electrode. Now, by means of the pH conversion, the EMF that develops in the product, and its temperature, are determined.

Further calculations are made by formulas.

What is titrated acidity?

The acidity of the product is classified as active and titrated.

To determine the second, it is necessary to use the alkali titration mechanism. In general, this is a complex chemical process, as a result of which titrated acidity in milk will be determined. Its degree is higher than 16-18 T. The titrated acidity of the colostrum is 5-6 T higher than that of normal milk. This is due to the fact that it significantly increased the level of serum proteins. And if you consider milk from sick animals or old milking, their acidity will be lower by 5-8 T than in a healthy animal. Such indicators are associated with the presence of chloride salts. Also, the titrated acidity, as well as the active acid, is greatly influenced by the conditions in which the animal is kept, its genetics, nutrition, breed and health. For example, if there is a lack of salts in the feed, the titratable acidity of the milk will be 23-24 T. At such rates, the product is subject to rapid souring.

In terms of titrated acidity, technological processes are controlled not only for milk, but for all dairy products that pass through lactic fermentation.

Quality standard

In Russia, there are requirements that milk must meet. GOST 31450-2013 is a quality standard that applies to drinking milk packaged in consumer containers after heat treatment. In accordance with the requirements, the product should not contain flakes, loose lumps of fat. In accordance with GOST, milk should have a white uniform color with a bluish - for a skimmed product, with a light cream - for a pasteurized and creamy shade for baked. An important indicator of quality is the absence of foreign smells and taste.

Due to its useful qualities, milk can replace a large number of products, but not one other product can not replace milk. In addition to fats, proteins and carbohydrates, which are in it in a balanced ratio, calcium is present in milk, which is easily absorbed by the body.