In addition to calcium supplement, milk has excellent protein quality and is rich in lactose, which is conducive to calcium absorption. In front of a wide range of brands, what should we focus on when purchasing milk? Li Guangyi, a doctor in the Department of nutrition of the fourth central hospital, gave a reminder. It's important to find out whether it's your milk or your drink before you get it. At present, the liquid milk on the market includes pasteurized milk, ultra-high temperature sterilized milk, reconstituted milk, fermented milk and milk containing beverage. Pasteurized milk is milk made from milk sterilized at low temperature. It only kills the nutrients of microorganisms, retains beneficial bacteria, and fully maintains the nutrition and freshness of milk. However, the shelf life is short and requires refrigeration. Ultra high temperature sterilized milk refers to the instant sterilization treatment for 4 to 15 seconds at the temperature of 135 ℃ to 150 ℃, which completely destroys the microorganisms and spores that can grow therein. The advantage is that it can be stored at room temperature for a long time, but the disadvantage is that it destroys a lot of nutrients. To restore the milk finger is to concentrate and dry the milk into concentrated milk or milk powder, and add the right amount of water to make the emulsion that is proportional to the water and solid content of the raw milk. Fermented milk is also known as yogurt. It should be noted that milk containing drinks are not real milk and should not be given to children. (outlook new era)