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How to test cow's milk for naturalness. Dairy products - natural and fake: how to distinguish? Identifying signs of starch

Milk or fake? This question arises every day for many people when we hold another carton or bottle of milk in our hands before purchasing it. Of course, when a person is healthy, then you don’t have to think about it, but if there is a child in the family for whom it is very convenient and useful to prepare milk porridge, what should you do? Nobody wants to be poisoned by the invention of the modern chemical industry, therefore, in this article we will consider with you, dear readers, how to distinguish real milk from fake.

1. On a container with real milk it must be written “Milk”. This may sound funny, but only at first glance. The law sets a standard that every product must meet. Some manufacturers, in order to “promote” their product, which looks like milk, to circumvent the law, use the words “Dairy product” or “Milk drink” instead of “Milk”. It turns out that by law they do not sell milk, but an inattentive buyer, tempted by an affordable price, can buy a magical chemical mixture, or a drink made from milk powder (powder).

2. Pour some milk into a transparent glass. Stir it. If there is a white mark left on the inner walls of the glass that is in no hurry to flow down, this may indicate that the product has fat content, which means there is a high probability that the milk is real.

3. Pour half a clear glass of clean water. Add some milk to it. If the product instantly dissolves in water, then it is fake milk, but if it sank to a greater extent to the bottom and, as it were, created a lower whitish layer, then it is milk.

4. Leave a glass of milk for a day to sour. Real milk will taste sour, forming curdled milk separated from the whey. If it is a fake, the product will have a bitter aftertaste that bears little resemblance to anything related to milk.

5. Apply a drop of milk to your nail. It should not spread instantly. Also, dip a spoon into a glass of milk and take it out. Milk should not flow from it like water, i.e. slowly.

6. Real milk cannot be stored for a long time, so as not to turn sour. If the shelf life of the product indicated on the packaging is 10 days or more, it is a fake. If, after opening, it can stand for more than 5 days, it is also a fake.

7. Add a couple of drops of iodine to a small amount of milk. If the milk is real, i.e. natural, it will turn iodine-colored and slightly yellow. If the product turns bluish and other shades, then it is a milk drink.

How do you distinguish milk from counterfeit milk?

Where can I get real milk?

If you have the opportunity, try to buy milk somewhere in the village. But here, too, not everything is so simple. If you take this wonderful cow product on an ongoing basis, after the first time, submit it for examination so that the laboratory can determine whether the milk yield is produced from a sick cow, and whether it contains pathogenic microorganisms.

A couple more lines about security measures...

If a person is a city resident and eats mainly products from the supermarket, then after drinking homemade fat milk, there is a high probability of diarrhea.

Before drinking real homemade milk, be sure to boil it. This minimizes possible gastrointestinal diseases caused by various pathogenic microorganisms.

In general, prayer with thanksgiving is wonderfully suitable for cleansing not only milk, but also other foods, for as it is also written in the Holy Scriptures: “And nothing is reprehensible if it is received with thanksgiving, because it is sanctified by the word of God and prayer.” (1 Timothy 4:4,5). Therefore, before eating food, thank God for it, and ask Him to cleanse and sanctify it for you, and then everything will definitely be fine!

Health to you, dear readers, peace and goodness!

Zakharova Ekaterina

Research work on the topic "Determining the quality of milk at home." Purpose of the work: acquiring the ability to determine the quality of milk. Objective: learn to distinguish a high-quality product from a low-quality one.

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Department of Education

Vyksa district, Nizhny Novgorod region

Municipal budgetary educational institution

secondary school No. 8

Category: research

Determination of milk quality

at home

MBOU Secondary School No. 8

Head: Volkova

Elena Vyacheslavovna,

Teacher

Primary classes

G. Vyksa

2011

1. Setting goals, problems and research methods p. 3

2. Justification of the topic p. 4

3. Methods for determining the quality of milk p. eleven

5.Do you know what? With. 22

6. Conclusions p.24

7. Applications p.25

8. Literature review p. 28

Subject :

Determining the quality of milk at home

Target:

Acquiring the ability to determine the quality of milk

Task:

Learn to distinguish a quality product from a low-quality one

Formulation of the problem:

Milk, one of the most importantproducts that a person consumes. It is a raw material for the production of fermented milk products, cheeses, and butter.

Do we always consume high-quality milk?

Is it possible to determine the quality of milk at home?

Problem research methods:

1. Experiment
2. Observation
3. Study
4. Comparison of facts
5. Analysis of results
6. Processing the results
7. Ratings
8. Literature analysis
9. Formulation of conclusions

Milk is an amazing food

prepared by nature itself.

Academician I.P. Pavlov

JUSTIFICATION OF THE TOPIC

Humanity began to use milk, like bread, for food more than five thousand years ago. Milk is the only food product in the first months of human life. It is also extremely important in the nutrition of adults. For old, weak and sick people, milk is an indispensable food.

It has been established that this product contains over one hundred valuable components. It includes all the substances necessary for the functioning of the body: proteins, fats, carbohydrates, mineral salts, vitamins. These milk components are well balanced, making them easily and completely digestible.

Milk is one of the most important human food products. Milk and a great variety of dairy products add variety to the diet, improve taste, increase the nutritional value of our food and have enormous dietary and medicinal value. “If you drink one liter of milk every day for 1200 months, you will provide yourself with a hundred years of life!” - said the Swedish scientist Nile Gustafson jokingly. These words of the Swedish scientist are confirmed by experimental data, because milk contains all the substances necessary for the body.

Since ancient times, milk has been used as a remedy for many diseases: in the treatment of the heart, kidneys and other organs.

Dairy products (yogurt, kumiss, kefir, etc.) are an excellent remedy for people suffering from gastrointestinal diseases and tuberculosis; They also give a good effect in cases of poisoning.

The ancient Egyptians used donkey milk for medicinal purposes. Scientists of Ancient Rome and Greece recommended milk for the treatment of consumption. Hippocrates attributed different healing properties to different types of milk, for example, goat and mare milk - the ability to cure consumption, cow milk - to cure gout and anemia, donkey milk - many diseases.

In our country, whole cow's milk is most often consumed, and dairy products are also prepared from it.

Milk is the most valuable product in the Universe, since it contributes to both physical and spiritual development of a person. Milk effectively treats mental disorders - irritability, fussiness, overstrain, pacifies and relieves insomnia. Our grandmothers knew that the best remedy for insomnia in a child is milk. The child was given a glass of warm milk with honey to drink at night, he slept soundly and became calm. If a person drinks milk at night, then he becomes more intelligent, begins to better understand the world around him, and acquires a correct vision of good and evil - the Eastern sages believed. They also recommended drinking it either late in the evening or early in the morning, sweetening it with honey orsugar, adding spices: fennel, cardamom, turmeric, cinnamon, saffron and licorice. Moreover, milk, which some attribute to the ability to increase body weight, in fact, on the contrary, can protect the body from gaining excess weight.

What is the composition of whole milk?

Whole milk contains almost equal amounts of protein, fat and carbohydrates. The average composition of milk is approximately as follows:

Water - 87.2%,

dry matter - 12.8%, including

fats - 3.9%,

squirrels - 3.4 (casein - 2.7, albumin - 0.6, globulin - 0.1),

milk sugar - 4.7%.

Vitamins milk contains about 30. There is especially a lot of vitamins A and B, and enriched vitamins D. Milk has everything you need to build blood, nervous tissue, muscles and bones. Milk is not a mechanical mixture of different substances. All substances that are contained are either dissolved in it, or like fats and proteins are in solution in tiny particles. Milk is a homogeneous and thin mixture.

The quality of milk depends on many indicators: feed, processing methods, animal care methods. A cow of the same breed, depending on climatic conditions, feeding, and maintenance, produces different amounts of milk, and its quality also varies. The composition of milk varies depending on the time of year, the age of the cow, and its individual characteristics. Feed affects the quality, some of them (rutabaga, turnips, cabbage, cabbage, tops, sugar beets and silage) can give the milk an unpleasant taste and smell, especially when fed in large quantities.

Nizhny Novgorod milk differs in its composition and quality from many other Russian producers. This is due to the agroclimatic conditions of our region, but the quality program “Buy Nizhny Novgorod!”, which was adopted by the government of the Nizhny Novgorod region in 2007, plays an even greater role.

On January 1, 2009, a new milk regulation came into force, according to which all dairy products must meet new quality requirements. Only whole milk will be used for the production of dairy products. Natural dairy products from Nizhny Novgorod producers will be marked with a special quality mark. The product label will indicate that it does not contain artificial colors or powdered milk. High-quality products are awarded a quality mark in the form of an emblem with an image of a green leaf and a blue drop of water with the note “Without artificial components and GMOs.”

It is this special sign on the packaging, symbolizing the purity of nature and everything that grows on Nizhny Novgorod land that nourishes and feeds its inhabitants.

How to avoid deception?

What do you need to know when buying such a necessary product for us as milk?

You need to know some methods for determining its quality. Every buyer can do this. I want to give some recommendations that will help you buy a quality product.

Every buyer should pay attention to the packaging - it is the calling card of the product, than itcheaper, the shorter the milk will be stored.

I want to do my own home research as well.

Methods for determining milk quality

How can we determine whether we are buying quality milk or not?

For the experiment, I took whole homemade milk, sample No. 1

and milk from famous Nizhny Novgorod producers:

Milk "Northern Valley" - sample No. 2

Milk “Jolly Milkman” - sample No. 3

Milk "Vyksunskoe" - sample No. 4

And compared them.

Experience 1:

The quality of milk can be determined by its appearance

Equipment: glass beaker 250 ml.

Progress:

1. Pour milk into a glass to the middle of the volume.

2. Carefully examined the milk for the presence of contaminants and impurities and noted its uniformity.

3. Let the milk sit for 3-5 minutes and note the presence of sediment. (See Appendix No. 1)

Experience 2:

Determining the consistency of milk

Equipment: chemical test tubes

Progress:

1. Pour milk into the test tube to the middle of the volume.

2. Closed the test tube and shook it slightly to wet the walls.

3. I let the milk drain and assessed the result within 1-2 minutes. (See Appendix No. 1)

Experience 3:

Determining the smell of milk

Equipment: test tube with stopper.

Progress:

1. I poured a little more than half of its volume into a test tube and closed it with a stopper.

2. I opened the test tube and immediately smelled it. The smell is determined by repeated short sniffs. (See Appendix No. 1)

Experience 4:

Quality milk determines its color.

Equipment: chemical test tubes, white sheet of paper.

Progress:

1. Pour milk into test tubes.

2. She brought a white sheet of paper to the test tube and compared the color. (See Appendix No. 1)

Experience 5:

Determining the taste of milk

Equipment: glass beaker, drinking water.

Progress:

1. Pour 10-20 ml of milk into a glass.

2. She took a sip of milk into her mouth, trying to distribute it throughout the entire oral cavity, and held it for a while. Determined the taste.

After each milk sample, you should rinse your mouth with water and take short breaks between individual determinations. (See Appendix No. 1)

After conducting all these experiments, I compiled a table and entered the data obtained into it (see Appendix No. 1).

Experience 6:

Determination of the purity of milk

Materials and equipment:

Measuring tubes, cotton filters, funnel, glass.

Progress:

1. Placed a cotton filter in the funnel.

2. Lowered the funnel into a glass to collect filtered milk.

3. Pour 50 ml of milk onto the filter.

4. After all the milk has been filtered, carefully remove the filter and place it on a sheet of paper to dry.

5. Compared the contamination of the cotton pad with the standard standard. (See Appendix No. 2)

Experience 7:

Determining the presence of impurities in milk

Materials and equipment: test tubes with milk, cotton filters, acetic acid

Progress:

1. Strained the milk through cotton filters.

3. Observed what was happening with the milk. The appearance of bubbles in the milk indicates the presence of harmful impurities. (See Appendix No. 2)

Experience 8:

Determination of the presence of starch in milk

Materials and equipment: test tubes with milk, iodine solution.

Progress:

1. Pour 5-10 ml of milk into a test tube.

Milk with added starch turns blue, and pure milk turns yellow. Diluted milk has a floury or starchy taste that is very difficult to hide. (See Appendix No. 2)

After carrying out all these experiments, I compiled a table and entered the data obtained into it (See Appendix No. 2).

I chose this topic because I really love milk. It saturates the body with vitamins and gives me strength to study well. I would like to learn more about the beneficial properties of milk and talk about them so that all children drink milk and are healthy.

Milk should be included in the diet of every schoolchild. Just one glass of milk partially compensates for the breakfast the student missed.

The beneficial properties of milk are written in the scientific literature. I decided to find out if the students in our class drink milk drinks, do they know about their beneficial qualities? What drinks do the students in our class think are healthy? And which ones are delicious and loved?

Students of grade 4 “b” of secondary school No. 8 in Vyksa compiled ratings of healthy and favorite drinks.

So, the top three healthy drinks, according to my classmates, included: - milk (Hurray! In first place!);

Tea;

Cocoa (see Appendix No. 3)

But the favorite drinks were the following:

Juice;

Tea;

Carbonated water (see Appendix No. 3).

Analyzing the results of the survey, I realized that many students in the class consume drinks that are of little use or are generally harmful to the child’s body. Therefore, together with the class teacher, we decided to hold a class hour in the classroom on the topic “About tasty and healthy food” with the involvement of the pediatrician and the head of the school canteen. And also organize an excursion to the Vyksa dairy plant.

1. Humans first began to consume animal milk in the 8th-9th millennium BC, when the peoples inhabiting the Middle East managed to domesticate sheep and goats. In the 7th millennium, in the territory of modern Turkey, people began to herd cows, thus receiving one of the most popular modern products into their diet.
2. Nero's second wife, who was reputed to be a great beauty, always took 500 donkeys with her on trips so that she could take milk baths that improved her skin.
3. Cow's milk is the most consumed type of milk - its annual production exceeds 400 million tons!
4. An ancient sign indicating that milk will sour faster during a thunderstorm is still valid now, when the conditions for the production and storage of milk have changed dramatically.
5. The fattest types of milk are seal milk (the fat content in it exceeds 50%) and whale milk (up to 50% fat). The least fatty milk is produced by donkeys and mares.
6. So-called soy milk is produced from soybeans, which is eaten or used in cooking in the same way as cow's milk. It contains beneficial amino acids, vitamins and minerals, but its calcium content is low. In this regard, manufacturers often saturate soy milk with calcium salts.
7. Of all plant proteins, almond protein is closest to the protein of mother's milk, which is why it is often used to produce infant formula. The domestic animal whose milk is closest in composition to human milk is the donkey.
8. 250 ml of milk contains 300 mg of calcium. This is as much as 7 sardines, 2.5 cups of raw broccoli, 3 cups of peanuts or 4 cups of black beans.

End of form

Conclusions :

1. The milk samples we examined showed that they meet the quality standards that apply to milk.

1. Samples from Nizhny Novgorod producers do not differ much in performance from whole homemade milk. A slight starch content is allowed in packaged milk (sample No. 4). It is added to create the consistency of the product.

1. If you do not have the opportunity to drink whole homemade milk, you can drink milk from Nizhny Novgorod producers with a quality mark.

1. 25% of the classmates I surveyed consider milk to be a product necessary for the child’s body, but, unfortunately, only 10% of the children surveyed drink and love milk drinks every day.

1. I hope that my work will help children learn about the benefits of milk and dairy products. They will definitely include it in their diet. This means they will get sick less and study better!!!

Appendix No. 1

Appendix No. 2

Internet resources:

1. http://www.LifeOkey.ru/view_post.php?id=86

2. http:// www.nachalka.com/nod/284

3. http://psylib.org.ua/books/aurob04/txt14.htm

You can check the quality of milk at home. To do this, you do not need to conduct complex laboratory tests; it is enough to have what is always at hand.

Litmus

It is likely that not every home has a paper indicator, but if you set out to check the quality of food products, it is easy to purchase one at a pharmacy.

So, there are strips of litmus paper. What's next? Next, soak one strip of indicator paper in milk brought from a store or market, wait 1-2 minutes and carefully examine the litmus strip.

Coloring litmus paper blue will indicate the presence of soda or other alkalis in milk; litmus paper will react red to an acidic environment resulting from the addition of acid-based bleaches to milk.

If the color of the litmus strip of paper has not changed, you can quietly rejoice - no one added soda, boric and salicylic acid to the milk you bought.

Iodine

The presence of starch, which is added to milk to give it thickness, can be easily and quickly determined using ordinary milk.

Add a few drops of an alcohol solution of iodine to a small amount of milk. If the milk turns blue, it means starch is mixed into it, and a yellowish-orange color indicates its absence in the milk.

Alcohol

Using this, you can accurately determine whether milk is diluted with water if you add 2 parts of alcohol to 1 part milk, and then vigorously shake the resulting mixture for 1 minute.

After finishing shaking, immediately pour the mixture of milk and alcohol into a plate or saucer, carefully observing the state of the mixture and recording the time after which white flakes appear in it.

The rapid (within 5-6 seconds) formation of casein flakes released from the alcohol whey will indicate the high quality of the milk, but if the flakes appear with a significant delay, you should know that the milk has been diluted with water.

By the time of formation of casein flakes, one can judge the degree of dilution of milk with water. If it took about a minute for flakes to form, 20% of the milk volume was replaced with water, a time interval of 25-30 minutes would indicate that the milk contained 40% water, and if casein flakes began to appear only after 40 minutes, such milk was diluted by half with water.

Warm water

By pouring a small amount of milk into a glass with a warm thin stream, you can determine with a high degree of probability whether it was previously diluted with water.

High-quality milk in the form of a white clot will collect at the top of the glass; diluted milk will behave differently - it will almost completely dissolve in the water, turning it dirty white.

Filter paper

Another way to determine the degree of dilution of milk with water. In the absence of filter paper, you can use a paper napkin or toilet paper, the main requirement is that they must be of sufficiently high quality.

Dip a thin stick, toothpick or match into the milk and place a small drop of milk on the surface of the filter paper. It is very important that it be as small as possible and at the same time be as convex as possible, resembling a hemisphere in shape. To ensure the reliability of the result, it is better to use several such drops.

Since the filter paper has a finely porous surface structure, it will begin to absorb the water contained in the milk. In this case, a wet ring will appear on the surface of the paper around the drop; the width of the ring will be greater, the greater the water content in the milk.

A drop of undiluted milk will create a wet ring around itself no more than 1 mm thick, which will dry in about 2 hours at room temperature. The water ring around a drop of milk diluted with 10% water will be noticeably wider and will dry faster - in about an hour.

In half an hour, a ring around a drop of milk diluted by 30% will dry, and it will take only 10-15 minutes for a ring left by a drop of milk diluted half and half with water to dry.

Unfortunately, it is impossible to check at home whether the purchased product is natural or made from milk powder. But checking milk for the presence of antibiotics and various substances that slow down the growth of bacteria is very simple.

Natural and without additives milk, left at room temperature, should last 24 hours. If this does not happen, then there is a lot of chemistry in it.

Let the milk you buy always be high quality, whole and natural!

When buying products in a store, we cannot always be sure of their quality. Especially when it comes to dairy and fermented milk products. It has long been known that store-bought milk is of little benefit, and expired milk is even less beneficial. Many people, despite this fact, do not stop loving and preparing dishes based on it. There are basic options for assessing the quality of milk and its suitability for consumption.

How to determine the freshness of milk

The composition of cow's and goat's milk has several differences, but the freshness of this product is subject to the same check. Cow's milk contains casein, which, unlike goat's milk, can cause an allergic reaction. For this reason, not all people are susceptible to this type of product. Two types are known to contain pure protein.

In the old days, the freshness of milk was checked in the following way: housewives took an unlit match and threw it into a glass. If she hasn't drowned, the milk is fresh and ready to drink. Let's look at several ways to check product freshness.

Method No. 1. Soda
Pour half a glass of milk, add 10 grams. soda, watch the reaction. The appearance of foam indicates that the product is not fresh.

Method No. 2. A drop
Unlike store-bought milk, homemade milk is famous for its high fat content. Checking the indicators is quite simple. Dip a toothpick into a container of milk. Place a drop of milk product on your nail. If the drop does not spread, the liquid can be considered fresh.

Method No. 3. Boiling
Pour a small amount of milk into a heat-resistant container. Place on the stove and wait until the first bubbles appear. If the liquid begins to curdle, you can be sure that the dairy product is spoiled. Don’t forget about your own sense of smell, because this is a simple and sure way to determine the freshness of milk. It should not contain any strong odors and be uniform (without clots).

Checking the fat content of milk

To test milk for fat content, you will need any water content tests. If the product is diluted, the fat content is reduced significantly. There is another proven method.

Take two containers and fill one with milk. Pour the liquid from the first bowl into the second. Evaluate the result. If the milk is fatty, it will not leave marks on the walls of the vessel. A diluted product, on the contrary, will be smeared over the entire surface of the container, indicating the content of water or palm oil in the composition.

Assessing milk quality: important aspects

Many people who do not take store-bought milk seriously often speak negatively about the quality of the product supplied. They believe that cottage cheese, kefir, fermented baked milk and, of course, milk are prepared exclusively from powder.

An effective way to assess the quality of milk is to visually assess the shade. If the composition is yellow, you have good goat or cow milk. In this case, a snow-white or white with a blue tint indicates the participation of chemical impurities.

Unscrupulous manufacturing companies supply their products with starch (potato, corn), lime, flour or chalk. The listed components improve the aesthetic performance of the finished composition.

Identifying signs of starch

Most often, when producing skim milk, starch is added, so the product becomes thicker. To determine the presence of this substance you will need iodine. Pour a partial glass of milk, add a few drops of iodine. Observe the reaction: if the liquid is predominantly blue, the milk contains starch. Otherwise, the presence of yellowish circles indicates the absence of additives in the milk.

Detection of water in milk

Some factories and farmers, due to a weakness for money, make low-quality products. Thus, they use an annoying trick, that is, they dilute the milk with water.

Method No. 1. Alcohol
This test option is only suitable for cow's milk because it contains casein. Mix medical (ethyl) alcohol and milk in a 2:1 ratio. You can replace alcohol with high-quality vodka. Shake the prepared mixture for one minute, then pour the contents onto a flat plate. If the milk is of high quality, flakes will form on the surface of the saucer within the first seven seconds. If there are few flakes and much more time is spent on their formation, this means that the milk contains a lot of water.

Method No. 2. Warm water
The technique is developed for any type of milk (goat, cow). Pour a glass of warm water, then slowly add milk. As a result, when mixing two liquids, high-quality milk will curdle, and diluted milk will mix with water.

Check for impurities

Often store-bought products are not of high quality. Unscrupulous manufacturers stuff milk with flavor enhancers and other impurities that can increase the shelf life of the composition. To exclude the harmful effects of milk on the human body, it is necessary to conduct a thorough check.

Antibiotic Availability Assessment

For long-term storage of dairy products, antibiotics are added. It is not difficult to detect the presence of these drugs. It is enough to leave the liquid in a container with an open lid at a temperature of 25 degrees. If the milk is of high quality, the fermentation process will begin (the composition will become similar to a jelly-like mass). If nothing like this happens to the liquid, this condition indicates the presence of antibiotics in the product. They, in turn, slow down the spread of lactic acid bacteria.

Assessment of acetylsalicylic acid and soda content

The pursuit of extending shelf life leads to manufacturers stuffing milk with acetylsalicylic acid and soda. It is not difficult to determine the presence of such substances; let’s consider the main methods.

1. Litmus paper. First of all, dip the plate in milk, then evaluate the result. The soda content is characterized by a blue color, and the presence of acid is red.
2. Vinegar essence. Take a glass of milk and add a few drops of essence. Bubbles may appear as a result of the chemical process. This effect indicates the presence of impurities. If nothing happens, you can be confident in the quality of the product.
3. Nitrous acid. Many manufacturers prepare milk from low-fat powder. The naturalness of the product can be checked using nitrous acid (sold in household stores). Pour the milk into a container and use a pipette to add the acid one drop at a time. In case of yellowing and darkening, the product is unnatural.
4. Visual inspection. It is not always necessary to resort to chemical experiments. Sometimes it is enough to shake the milk and determine its naturalness by eye. In a glass container, opaque grains of product will remain on the walls.

It is not difficult to assess the quality of milk if you have sufficient knowledge regarding possible methods. Check store-bought products for impurities, pay attention to fat content and freshness. Use effective methods, do not violate the instructions.

Video: how to check milk quality at home

How to check the quality of milk

Milk test - checking the quality of milk at home

1. When purchasing, pay attention to the expiration date of milk and storage conditions. Buy only dairy products where there is refrigeration equipment. As for the market, decide for yourself whether it’s worth the risk. And please note that two hours is the maximum time for transporting fresh milk without using a refrigerator.

2. To test milk at home

purchase litmus paper. It will show the presence of chemical impurities in the milk. If the milk is not diluted, then the litmus test will remain unchanged. Litmus paper will determine whether there is soda in the milk (in an alkaline environment, litmus paper will turn blue). Soda is added to keep milk longer. How to check the quality of milk

3. Also, in order to prevent the product from turning sour for as long as possible, salicylic acid can be dissolved in milk. If it is present in milk, then the litmus paper will turn bright red.

4. To increase the thickness of milk

unscrupulous manufacturers may add starch. To check, you can drop iodine into the milk. If the milk turns blue, it means there was some “innovation”! How to check the quality of milk

5. To increase the volume, milk is diluted with water. Test with alcohol (vodka). Pour a little milk into a glass, add alcohol (vodka) to the glass twice as much as milk. Mix everything. If the milk is of high quality, then flakes will appear; this is because the casein protein has coagulated from the alcohol. To better see the flakes, you can pour the mixture into a saucer of a single dark color. In diluted milk, flakes do not form immediately, but after some time. The more water in the milk, the later the flakes will appear.

6. How can you detect chalk in milk?

To do this, you can pour vinegar. If there is a lot of foam, it means there is chalk in the milk.

7. Long-term testing for milk quality. Defective milk will not pass this test!

How to check the quality of milk. Take a dry, clean glass and pour milk into it. Cover it with a napkin and leave it on the table. Do not stir during observation.

Normal milk

it should taste sour within a day (maybe earlier, it all depends on the temperature in the room).
The next stage of milk transformation is curdled milk; the sour taste should be greatly reduced. The curdled milk should be a homogeneous mass, like jelly, that mixes easily. How to check the quality of milk

What can be noticed during observation and what conclusions can be drawn about the quality of milk:
— The milk turned sour in more than a day. This means that the milk contains preservatives.
— Initially, milk has a boiled taste. This indicates that the milk was boiled or contains a concentrate.
— It doesn’t sour at all and after a while a foreign smell appears in the milk. This indicates that this is not natural milk, it is a surrogate (maybe powdered).
— It sours in time, but yogurt does not form in the form of a single jelly-like mass. This means that the milk was diluted with water.
— It sours in time and forms curdled milk of the required consistency, but a thin sour cream film has not formed on the surface of the curdled milk. This means that skim milk, i.e. partially driven through a separator, it was either diluted with skim milk (not water), or the milk was simply not fat.

How to check the quality of milk