When boiling milk, I found that there was a layer of white and white at the bottom of the pot. As th

Milk boiled for a long time will produce "milk scale", these white precipitates stuck to the bottom of the pot are mainly calcium and protein, and a lot of nutrients are lost in vain As long as the milk is boiled, many nutrients will be lost after a long time of boiling, such as a long heating time, the gelatinous protein particles in the milk appear dehydrated, from the original sol state to the gel state and precipitation. In addition, the phosphate in an unstable state is converted from the original acidic calcium phosphate into an insoluble neutral calcium phosphate precipitate. Long heating time, lactose in milk.

It will caramelize, not only browning the milk, but also gradually decomposing to form lactic acid.

At the same time, a small amount of potassium acid is produced, which gives the milk a sour taste. The heating time is long, and the milk contains a small amount of vitamin C

It will also be destroyed.

Remember.

There are two main possible causes of the white sediment that forms on the bottom of the pot when cooking milk.

First, the protein in milk may be denatured at high temperatures, combining with the calcium in brown sugar to form calcium oxalate, which is difficult to dissolve. This precipitate may be a white residue of calcium oxalate.

Secondly, the lactose in milk also breaks down at high temperatures to produce crystals. These crystals form white precipitates at low temperatures.

Therefore, from the perspective of the list of ingredients and the production steps, the white sediment that appears when boiling milk is normal and will not cause harm to the human body.

It can't be eaten, and there is sediment in boiled milk, which means that the milk has gone bad. Spoiled milk is treated as spoiled milk when sediment or tofu curdles after heating. The identification method of heating is suitable for fresh milk, high-calcium milk and flavored milk beverages. However, yogurt and lactic acid bacteria drinks should not be heated.

Normal milk is milky white or light yellow, and if the milk has sediment or abnormal color, it is spoiled. If you have a broken or abnormal packaging of the milk, do not drink it.

Because the temperature of the pot is too high, it will cause the milk to paste the bottom when boiling.

In order to prevent the milk from sticking to the bottom when boiling milk, pour it slowly when pouring the milk, do not bring it along the edge of the pot, and it is best to stir while boiling the milk, which can effectively prevent the milk from sticking to the bottom. When cooking, you should control the heat, first simmer slowly, and then increase the heat after the pot is hot.

Relevant knowledge. It is best to use low heat to boil milk, and at the same time, it should not be boiled for a long time, otherwise it will be easy to paste the bottom. Pasteurization is currently a more advanced method of fresh milk processing, which can not only preserve the nutrients in fresh milk, but also kill harmful bacteria in milk, so that the processed milk is delicious and pure.

Put the packaged fresh milk or fresh milk into a heated container, such as a cup, and then soak and heat it in hot water at 40 to 50 °C for 3-5 minutes, and then drink it when the taste is warm. If you choose microwave heating, be sure to set the force and time parameters in advance, it is recommended to use medium heat or low heat, and heat it in two or three times, that is, take it out after each heating, shake it evenly, and then heat it until the milk is warm and not hot.

The color of fresh milk should be white or slightly yellow in white, and should not be dark yellow or other colors; The milk is homogeneous, and there should be no tofu brain-like precipitate at the bottom of the bottle. The sale should have a milky smell and should not have an abnormal smell. The delicious taste formed by the fusion of four kinds of tastes, sweet, sour, salty, and bitter is a normal fresh milk taste, and there should be no bitterness, astringency and other peculiar smells.

No, it's oozing milk skin.

Milk skin is mainly formed by fat floating, but it is not only made up of fat. During the heating process of milk, the milk fat will swell, and the viscosity of the milk will decrease, and these reactions will promote the rise of the fat, so that the fat will accumulate on the surface of the milk. As the heating continues, the fat globulin proteins are denatured, resulting in unstable fats that can easily coagulate together.

At the same time, these coagulated milk fats will also adsorb casein and whey protein in milk, reduce the tension on the surface of milk, and finally form a more stable film, which is the "milk skin" we see. Therefore, in terms of composition, there is fat in the "milk skin", and there are also some proteins adsorbed, and it is okay to eat it.

Summary. Dear, for you to find out that after the pure milk is boiled, there is a layer of yellow at the bottom of the pot, and the layer of yellow substance formed on the top of the milk after heating is the milk skin. In the process of milk heating, the expansion of milk fat and the decrease of emulsion viscosity promote the rise of fat, so that the fat accumulates to the surface of milk, with the continuous heating, the fat globule membrane protein is denatured, and the fat that loses the fat globule membrane is unstable and easy to coagulate together, At the same time, the coagulated milk fat will also adsorb casein and whey protein in milk, reduce surface tension, and finally form a more stable film, which is "milk skin".

Dear, for you to find out that after the pure milk is boiled, there is a layer of yellow at the bottom of the pot, and the layer of yellow substance formed on the top of the milk after heating is the milk skin. In the process of milk heating, the expansion of milk fat and the decrease in the viscosity of the emulsion promote the rise of fat, so that the fat accumulates to the surface of the milk, with the continuous heating, the fat globule membrane protein is denatured, and the fat that loses the fat globule membrane is unstable and easy to coagulate together.

Here's that thing.

Pure milk boiled out.

Kiss, it seems that the pot is boiled, and there will be no problem if you change the pot.

Generally, after fresh milk is cooled, there will be a layer of milk skin on the surface, which is fat, indicating that the milk is better. If it is a milk powder, the milk powder is clumped, which means that the water temperature is too high and destroys the protein. Or the milk powder is not good, or it is not fresh.

Generally, it is good to use warm water for milk powder, not too hot water.

Consumers should pay attention to the following points when consuming it:

1. Pour 7 parts of 65 or so warm boiled water into a clean container, and then put in 1 part of milk powder, or you can determine the amount of milk powder according to your own needs, let it dissolve naturally, and then stir to make it completely dissolved before drinking.

2. Do not use boiling water for the water used to make milk powder, because the water temperature is too high, which will cause clots in the whey protein in the milk powder, affect digestion and absorption, and reduce the nutritional value of milk powder.

3. It is best to drink a cup of milk powder at night before going to bed to help you sleep peacefully. Powdered milk should be consumed with other foods at breakfast.

4. Do not drink milk on an empty stomach, because when fasting, the milk stays in the stomach for a short time, can not be fully enzymatically hydrolyzed, and soon enters the intestines, affecting the digestion and absorption of milk.

Protein denaturation.

It is better not to boil the milk, warm it is fine.

The method of heating with a water bath is more scientific.

That is, put the milk in warm water at a certain temperature for a period of time, and then you can eat it!

No, maybe your water temperature is too high, like the ginger milk in the restaurant is this principle, the surface is a layer of milk skin, if the expiration date is normal phenomenon.

No? That's the main nutrient of milk. If you drink that white one, you don't have to drink anything, that's what the doctor said.

Most of it is fat.

In the process of milk heating, the expansion of milk fat and the decrease of emulsion viscosity promote the rise of fat, so that the fat accumulates to the surface of milk, with the continuous heating, the fat globule membrane protein is denatured, and the fat that loses the fat globule membrane is unstable, and it is easy to coagulate together, at the same time, the coagulated milk fat will also adsorb casein and whey protein in milk, reduce surface tension, and finally form a more stable film, which is the "milk skin" we see. Therefore, there is nothing wrong with saying that "the fat in the milk is boiled", but boiling the milk skin does not mean that there is no fat in the remaining milk, and the milk that has been skimmed does not equal skim milk.