How does milk become powdered milk?

Recently, after a news report that "an 8-month-old baby girl who was diagnosed with the disease did not eat milk powder after isolation, and raised 180 bags of breast milk in less than 3 hours", milk powder once again entered everyone's field of vision.

In recent years, the production of dairy products has attracted more and more attention. In the production of dairy products in my country, the production of milk powder accounts for about 80% of the total output of dairy products. So do you know how milk is turned into milk powder? Next, the editor will take you to find out together!

The manufacturing process of dairy products is roughly divided into: acceptance of raw milk→milk pretreatment and standardization→concentration→spray drying→cooling→packaging, in which milk pretreatment and standardization, concentration, and spray drying play a very important role in the production process. role.

Raw milk acceptance

The acceptance of raw milk includes sensory evaluation, alcohol test, physical and chemical index inspection, total number of colonies, adulteration inspection, melamine inspection, antibiotic inspection and other items.

Raw milk pretreatment and standardization

1. Cooling storage: After the raw milk is filtered, it is cooled to 4-6°C and stored in the raw milk storage tank for 36 hours, and the agitator runs automatically to prevent the fat from floating.

2. Preheating and sterilization: The stored raw milk needs to be sterilized at a high temperature of 85°C for 15 seconds to kill all microorganisms that cause human diseases and prolong the storage time of raw milk.

3. Preheating and separation: heat exchange the preserved raw milk through a plate heat exchanger, and after preheating to about 50°C, use the centrifugal force generated by the high-speed rotating centrifuge to throw the impurities in the milk to the centrifuge separation bowl The surrounding wall, and the impurities are regularly discharged to achieve the purpose of milk cleansing.

4. Homogenization: Mechanically process the fat globules in the milk to make the fat globules into smaller particles and distribute them evenly in the milk.

concentrate

After the milk has been pretreated and standardized, it is heated with an evaporator (concentrator), so that the water in the milk boils from liquid to gaseous, and the gaseous water is continuously discharged to obtain thick milk.

spray drying

In the milk powder production process, the drying section is one of the most important links in milk powder production, and the spray dryer, as an important tool for milk powder production, plays a very important role in the production process.

At present, the spray drying process is that the material is pumped into the spray dryer, and the atomizer disperses it into small droplets; the air is heated and sent into the drying chamber to mix and contact with the material mist; after the drying process is completed, the dried product After separation, it is stored in the warehouse or put into use directly.

The milk powder produced by the spray drying method is a uniform powder product. It does not need to be dried, jelly, crushed and other processes, and can be directly packaged as a finished product, which makes the milk powder production process mechanized, continuous and large-scale. The surface temperature of the material will not be too high, which improves the quality of the milk powder product.

Cooling and Packaging

Milk powder mini spray dryer machine

The temperature when it comes out is about 60-70°C. Milk powder packaged at high temperature tends to separate the fat, and small flakes composed of fat and protein are formed on the surface when brewing. Therefore, milk powder needs to be cooled to below 40°C before packaging. For large-pack milk powder, it needs to be cooled to below 30°C before packaging.