Breast milk is the most ideal natural food for nurturing new life. No other food can compare. There are numerous praises for it in ancient and modern times. About cow’s milk, “The Compendium of Materia Medica” called it “the effect of rejuvenation”, Alsipov, the father of Western medicine, called it “the food closest to perfection”, “white blood” and “the nanny of mankind”. “The famous nutritionist Yu Ruomu in China called it “nature’s jelly for human brewing”. Milk is rich in nutrients, easy to digest and absorb, good quality and cheap, its high nutritional value of other natural foods can not be compared. And it is easy to consume. After sterilization, milk can be consumed directly without any processing. With the strengthening of health consciousness, milk consumption in China is gradually increasing and becoming an important food in our daily life. “A glass of milk strengthens a nation”, and Japan, our eastern neighbor, is a good example. Japan in the post-World War II economic difficulties of the government to provide primary and secondary school students with a free glass of milk every day, Japan’s post-World War II generation of physical improvement of the world’s attention, the average height increased significantly, and become one of the longest life expectancy in the world. Other countries have also recognized the positive effects of milk on health, and more than 30 countries around the world have actively promoted milk programs to enhance national fitness. In November 2000, China’s “Milk for Students Program” was officially launched. Milk is an ideal nutritional food. Milk is an ideal nutritional food, as long as we consume milk scientifically and in the right amount, it can help improve nutrition and enhance physical fitness. Each 100 grams of pure milk contains 87 grams of water, 3.3 grams of protein, 4 grams of fat, 5 grams of carbohydrates, 120 milligrams of calcium, 93 milligrams of phosphorus, 0.2 milligrams of iron, 140 international units of Vit A, 0.04 milligrams of vitamin B1, 0.13 milligrams of vitamin B2, 0.2 milligrams of nicotinic acid, and 1 milligram of vitamin C. Available calories 69 kcal. The proteins in milk are mainly casein, albumin, globulin and milk protein, etc. It contains 8 essential amino acids for human body and has 98% digestibility. The fat globules in milk are very small, so it tastes fine and is extremely easy to digest. In addition, milk fat contains essential fatty acids and phospholipids as well as fat-soluble vitamins. Lactose in milk is is the most easily digested and absorbed sugar, which promotes the absorption of metal ions such as calcium, magnesium, iron and zinc. The minerals and trace elements in milk are in a dissolved state, and the ratio of the content of various minerals, especially the ratio of calcium and phosphorus, is relatively appropriate, which is easily digested and absorbed, making it an ideal food for calcium supplementation. In addition, lactose can also promote the growth of lactic acid bacteria in the human intestine, regulate the normal intestinal flora, to ensure intestinal health. With the development of social economy, China’s market has more and more milk names, the market of liquid milk and products in a variety of ways, just from the name of pure milk, fresh milk, pure fresh milk, yogurt, active milk, fruit milk, flavored milk, health milk, etc.. Consumers are confused. However, this is not the case in Western countries where milk drinking is more popular and has a longer history. It makes people worry whether the domestic milk products are now subdivided from the normal track, and does not exclude the suspicion of corporate hype concept. Milk nutrition is mainly based on several indicators such as protein, fat and dry matter to evaluate. Milk and its dairy products can be divided into two categories, pure milk and dairy drinks, depending on the ingredients. The pure milk without adding anything is the most nutritious. Even if there is a certain health function of sour milk, health function of the stronger active probiotic milk products, compared with the real pure milk nutrition is inferior. How to choose milk scientifically and reasonably? 1, the shelf life of milk is not the longer the better The raw milk is not directly drinkable, it may contain active pathogenic bacteria, such as Mycobacterium tuberculosis, Borrelia burgdorferi, foot and mouth disease, Staphylococcus aureus and so on. You should not drink freshly-milked milk in the blind pursuit of freshness and high purity. Milk sold in the market is sterilized, and there are two types of milk sterilization: “pasteurized milk” and “ultra-high temperature sterilized milk”. Different packaging and sterilization methods determine the shelf life of milk. Pasteurized milk is raw milk that is heated to 72-75 degrees Celsius for about 15 seconds to destroy pathogenic bacteria, yeast, mold and most other bacteria without damaging the milk nutrition. However, it does not achieve the degree of sterilization, and when the storage temperature exceeds 4°C, the bacteria in the milk can still reproduce, so it cannot be stored at room temperature for a long time, and needs to be stored in low-temperature refrigeration, and the shelf life is generally 1-7 days. Ultra-high temperature sterilized milk is milk that has been instantaneously sterilized (135°C to 150°C, 4 to 15 seconds) to completely inactivate microorganisms and spores in the milk. The product itself does not need to be refrigerated and can be kept at room temperature for more than 30 days. Some of the heat-resistant nutrients of milk, such as vitamins, will be destroyed, and the lactose in it will be caramelized. The proteins and lactose will also undergo a certain Merad reaction, causing the milk to brown and destroying the original flavor of the milk. From a nutritional point of view, pasteurized milk is safe and maintains the nutrition and flavor of milk, and is the best quality milk. 2, milk skimming is not the more thorough the better According to the amount of fat contained in milk, milk products are divided into whole, partially skimmed and completely skimmed milk. Pure cow’s milk fat content ≥ 3.1%, part-skimmed milk fat content 1.0% to 2.0%, skimmed milk fat content ≤ 0.5%. Whole milk is rich in flavor and smooth in taste, high in calories, and suitable for children, teenagers, pregnant women and the elderly. Semi-skimmed milk is suitable for the general public, especially the middle-aged. Skim milk is suitable for people who limit their fat intake, and the calorie content of skim milk is about 50% of that of whole milk. However, milk is not as good as skimmed. The fat is good for the absorption of fat-soluble vitamins and improves the flavor of the milk, besides, pure milk itself does not contain a high percentage of fat, so consumers should also choose whole milk according to their needs. 3, milk calcium content is not the higher the better Milk is rich in active calcium, each 100ml of milk contains about 125 mg of calcium. It not only has a high calcium content, but also contains Vit D, which can promote the body’s absorption and utilization of calcium, with an absorption rate of 98%, making milk the best food for calcium supplementation. The calcium content of milk itself does not vary much, but some manufacturing and operating companies continue to fortify calcium nutrition in natural milk in order to find selling points and artificially increase the calcium content of milk products. To add calcium to the milk may be the “snake adding foot” behavior, blindly adding calcium content not only reduces the absorption rate, can not be absorbed, and over time in the body precipitated or even cause stones. 4, aromatic and thick milk is not necessarily good milk The factors that determine the flavor of milk are mainly the milk fat content and the size of the fat particles. Usually, the higher the milk fat content (or milk fat rate), the stronger the milk flavor. The difference in protein and fat indicators of milk will not be too significant to produce significant fragrance and consistency differences. However, some dairy manufacturers add some flavors, thickeners, stabilizers, etc. to milk to meet consumers’ requirements for aromatic and thick taste, and artificially blend the flavor of milk to be very fragrant and thick. And a lot of added flavoring milk is not beneficial to the human body in the long run. At present, most of China’s milk producing cows are “black and white” Holstein cows, and their milk output is unlikely to reach this level of aroma. We should not measure the quality of milk by its aroma. The normal fresh milk aroma is not a foreign aroma, crisp but not sticky. 5, lactose intolerant people can drink sour milk Because of our people’s dietary habits to plant-based foods, many people do not often drink milk habits, infants weaned body lactase activity gradually decreased. As an adult, lactase activity is at a very low level and cannot digest and decompose lactose. Some people may experience lactose intolerance, i.e., abdominal pain, bloating, diarrhea and other symptoms after drinking milk. People who are lactose intolerant are better suited to drinking yogurt. Compared to milk, lactose in yogurt has been broken down into lactic acid, which does not cause lactose intolerance. The lactic acid bacteria in yogurt can enhance digestion, strengthen gastrointestinal motility, and the acidic environment promotes calcium absorption. In addition, people who are lactose intolerant can also choose to use softened milk, or use a gradual approach, drinking small amounts of milk for a period of time and then drinking milk after adaptation. It is worth mentioning that commercially available dairy beverages and milk are two different kinds of food. Dairy beverages use water and milk as the main ingredients, as well as sweeteners, fruit flavoring agents, flavors, colors, thickeners, organic acids and so on, and water often comes first (the national standard requires that the milk content should not be less than 30%). Although these dairy beverages are also called “so-and-so milk”, in terms of nutritional value, they are far inferior to milk, with protein, fat, iron and vitamin contents much lower than milk. Strictly speaking, these dairy beverages are not dairy products, but only beverages. The taste of dairy beverages is sweet and sour with various flavors, which is very popular among consumers, especially among children and teenagers. Although dairy beverages can be used to replenish water and a small amount of nutrients, they should not be consumed in excess. It is not scientific to consider milk drinks, lactic acid drinks, lactobacillus drinks, and even milk-flavored drinks as milk, and to consider drinking milk drinks as a major means of nutrition for children, not to mention that drinking such drinks should not affect normal meals. On the packaging of some dairy beverages commonly found in the market, there are often vague names such as “active milk”, “fresh milk” …… written in big conspicuous letters, but only when you look closely will you find a line next to it. The small letters “dairy beverage” or “beverage”, and individual irresponsible products do not even have this line of small letters. At present, the national production of milk drinks manufacturers, in addition to a small number of management level is higher, the production process is more mature enterprises, most small manufacturers produce milk drinks nutrient content does not meet the national standards, protein, vitamin A and calcium content is very little, and even a few unscrupulous manufacturers in order to save costs, only water, sugar, thickeners, flavors, etc. blended into milk-free milk drinks. This kind of shoddy drinks only have the taste of milk but not the composition of milk, not to mention the nutrition of milk, which will only spoil the appetite and affect the intake of nutrients. When buying, be sure to choose a product with a high brand name and complete and detailed logo, and look carefully before buying.