How to heat milk? Correct heating method of pure milk
4hw.com.cn: milk is the most common nutritional food in our diet. Most of the time, we drink milk directly. However, when the weather turns cold, many people want to drink a cup of hot milk to warm their stomach and heart. So how to heat the milk? Let's have a look!
Can pure milk be heated
It is better not to heat pure milk. The longer the milk is heated and the higher the temperature is, the more serious the loss of nutrition is. There are mainly vitamins, of which vitamin C is the most seriously lost, followed by lactose.
So, how to heat the milk correctly? In fact, the use of water separation heating method is the most appropriate. Drink a cup of about 250 ml milk and cook it at 70 ℃ for 3 minutes and 60 ℃ for 6 minutes. Then use the microwave for about a minute. But pay attention to the uneven temperature when heating in the microwave oven, so stir it before drinking so that it won't be scalded.
Experts pointed out that if heating can be avoided, try not to heat. Only in this way can we ensure the nutritional value of milk. Especially for children, good milk nutrition is more conducive to growth and development.
Can milk be drunk when it's bitter
The phenomenon of milk bitter often occurs in bagged and square boxed milk, especially the former. The main method of bag milk processing is ultra-high temperature instantaneous sterilization. This method can quickly kill bacteria and destroy the 'protein hydrolase' secreted by bacteria. Although the bacteria will not revive after being killed, a small part of the inactivated protein hydrolase may slowly restore the original protein structure during storage. Once the structure is restored, Their activity will also revive. The only effect of protein hydrolase is to cut the protein in milk into pieces, that is, hydrolyze it into peptides. Because the protein of milk is highly hydrophobic and some peptides have bitter taste, bitter milk is formed. However, although these hydrophobic peptides have a bitter taste, they are not toxic. In other words, this bag of milk can also be digested and absorbed by the human body and will not have a significant impact on health.
Don't worry too much about this, but drinking such milk makes people feel uncomfortable, so try to avoid it. Bitter milk and normal milk are difficult to distinguish with the naked eye, because it neither expands the bag nor flocculates. Before buying whole boxes of milk and boxed milk, pay attention to the production date of the product, try to buy fresh ex factory products, drink them as soon as possible, and avoid long-term storage. " After sterilization, it takes a long time for enzymes in milk to recover their activity, usually more than a month. Therefore, the taste of fresh milk is generally normal.
Precautions for drinking milk
1. First of all, milk should not be frozen for consumption
In life, some people want to be convenient. They buy bagged fresh milk enough to eat for a week at a time, and then put it in the refrigerator to freeze and take it with them. In fact, this is unscientific. After the frozen milk is thawed, there will be solidified precipitates, the floating fat mass has an obvious weak taste and abnormal smell, the liquid juice is water, and the nutritional value is significantly reduced. If stored too long, there will be food hygiene problems.
2. In addition, calcium powder should not be added to milk
Because the protein in milk is mainly casein, when calcium powder is added to milk, casein will combine with calcium ions to make milk solidify. When heating milk, other proteins in milk will also precipitate with calcium, thus affecting the absorption of nutrients. Milk itself is rich in calcium and maintains a reasonable balance with other components in milk. Under normal circumstances, precipitation will not occur. Therefore, there is no need to add calcium powder when eating milk.
3. The best time to drink milk is to drink a glass of milk before breakfast
The heat energy supply of breakfast accounts for 25% - 30% of the total heat energy demand, which can provide sufficient nutritional guarantee for the vitality of the day. Milk can also be drunk around 4 p.m. and about an hour before dinner. Drinking a glass of milk before rest at night can also help the human body absorb its nutrients and play a hypnotic role.
4. Children who take milk as their staple food should not drink more than 1kg of milk every day, otherwise there will be hidden bleeding in the stool
If a child drinks too much milk, not only can not supplement nutrition, but also prone to anemia, while the elderly are prone to cataract.
5. In addition, people suffering from colds, ulcers, cholecystitis, enteritis and other gastrointestinal diseases will get worse if they drink more milk
In addition, some people like to eat milk and chocolate together, which is also unscientific. Milk and chocolate will produce calcium oxalate from oxalic acid in milk, which will lead to calcium deficiency, diarrhea, dry hair, fractures and urinary calculi.