Milk is one of the oldest natural dairy products. It has the effect of reducing the pressure of esophageal sphincter, thereby increasing the reflux of gastric juice or intestinal fluid.Milk and its products are one of the important sources of protein, calcium, phosphorus, vitamin A, vitamin D and vitamin B2 in diet.So what are the nutrition of milk? What are the misunderstandings of drinking?
Nutritional characteristics
protein
The protein content in cow milk is 2.8%to 3.3%, mainly consisting of 79.6%casein, 11.5%whey (white) protein, and 3.3%dairy protein. There are a small amount of other protein, such as immunoglobulin and enzymes.wait.Cowlin protein, which is precipitated at PH4.6 at 20 ° C, is called casein.Telin is a heat -resistant protein, but it can precipitate under acidic conditions. Yogurt and cheese are made of this principle.Tyrts of casein and calcium and phosphorus in milk formatin gel particles, and the state of colloid suspension exists in cow milk.The milk protein is unstable to heat, solidify and precipitate during heating.Cowben protein digestion and absorption rate is 87%~ 89%, and biological value is 85, which is high -quality protein.
The fat fat is about 2.8%to 4.0%, and the particle -like fatballs are scattered in the lotion, which is very emulsified, which is easy to digest and absorb, and the absorption rate is as high as 97%.The lipids in cow milk are mainly triglyceride, a small amount of phospholipids and cholesterol. The fatty acid composition of fatty acids in milk fat is complicated, oleic acid accounts for 30%, linoleic acid and linolenic acid account for 5.3%and 2.1%, respectively.The content of buty acid, 己 acid, and bitterness) is high, which is about 9%, which is the reason why milk fat has a good flavor and easy to digest.
carbohydrate
The carbohydrates are mainly lactose, and cow lactose content is about 3.4%to 5.4%.Lactose can promote the absorption of minerals such as calcium, iron, and zinc in the intestine, and improve its biological utilization rate; promote intestinal lactic acid bacteria, especially bisidobacteria breeding, improve human micro -ecological balance, promote intestinal bacteria synthesis B vitamin B vitamin B vitaminsEssenceSome people have not drank milk for many years after adulthood. The lactase in the body is very low, and lactose cannot be decomposed. Lact sugar is decomposed and fermented by the intestine in the intestine, causing symptoms such as flatulence and diarrhea.This group of people can eat milk powder or drink yogurt.
Vitamin
Cow milk is almost related to the various vitamins required by the human body, and its content is related to breeding methods, seasons, processing methods, etc.For example, the content of vitamin A, vitamin D, carotene and vitamin C is significantly increased significantly in the shed in the sheds in the shed.The content of vitamin D in cow milk is low, but in the summer sunshine, its content has increased to a certain extent.In general, milk is a good source of vitamins B, which can provide considerable number of riboflavin, vitamin B12, vitamin A, vitamin B6 and pantothenic acid.
Mineral
The content of minerals in cow milk is about 0.7%to 0.75%, rich in constant elements such as calcium, phosphorus, potassium, sulfur, magnesium, and trace elements such as copper, zinc, manganese.100ml milk contains 110mg of calcium, which is three times that of human milk and high absorption rate. It is a good source of calcium.The ratio of calcium and phosphorus in milk is 1.2: 1.The content of potassium and magnesium in cow milk is also abundant, which is conducive to controlling blood pressure and becoming alkaline foods in animal food.However, the content of copper and iron is low and must be obtained from other foods.
Other substance
There are also a large number of physiological active substances in the milk, which are more important in it, immunoglobulin, biological activated peptide, common linoleic acid, tentinic acid, hormones, growth factor, and a variety of active peptides.Biological activated peptides are produced by hydrolyzed protein in the process of ductin, including sedative sacral peptides, antimedia peptides, immunosterial peptides, and antibacterial peptides.The content of milk iron protein in cow milk is 20 ~ 200ug/ml, which has the effects of regulating iron metabolism, promoting growth, and antioxidant. The peptide fragments formed by the hydrolyzed protease have a certain immune regulation effect.
Drinking misunderstanding
Milk beverage is milk
Some people think of milk drinks, lactic acid beverages, lactic acid bacteria beverages as milk.
Dont drink milk in summer
Some people think that summer is high in summer, and people will get angry after drinking milk in summer, but it is not.
Drink raw milk
Do not drink raw milk. There are a lot of bacteria in raw milk, and even viruses. All product factories are sterilized by instantly ultra -high temperature. The quality can be guaranteed.
Too many times of milk cooked or heated
A series of changes occur when milk is heated. After boiling, continue heating. The lactose in the milk starts to focus, and gradually decomposes into lactic acid and a small amount of methic acid. Vitamins are also destroyed.EssenceTherefore, hot milk should not be cooked for a long time.

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