Processing technology of milk powder
The production technology of milk powder can be divided into dry method and wet method.
The wet process is complex and needs more equipment. The main equipment for pretreatment is milk washing machine and homogenizer, preferably sterilizer, concentration equipment, drying equipment, packaging equipment, some auxiliary equipment, boilers and sewage treatment. The product has good uniformity and stable physical and chemical indexes. There must be a separator in the pretreatment equipment to make degreasing powder, and wet method is generally used.
Dry production process is relatively simple, mainly mixing machine, packaging machine and so on. The uniformity of the product is not as good as that of the wet method, but the heat-sensitive nutrients are easy to add. The requirements for the workshop are higher, and the CMP workshop is generally used.
To sum up, we can clearly see that milk powder production enterprises with milk source bases must adopt wet processing technology to treat fresh milk; The dry production process can be applied to manufacturers without fresh milk source, and the products can be obtained by purchasing industrial powder from other companies and dry mixing.
We know that only good raw materials can produce good products, and how can you guarantee the quality of products for manufacturers who can't even guarantee the source of raw materials? Then, smart consumers, you can learn about the processing technology from some articles promoted by enterprises, so as to judge the quality of products.
What is the production process of milk powder?
1. Acceptance and pretreatment of raw milk, namely milk.
From the acceptance of raw materials, the qualified milk is initially determined, and then the milk is purified. After getting the milk, some bacteria and even some magazines need to be preliminarily eliminated.
Step 2: seasoning
Ingredients: In the process of milk powder production, except for a few varieties (such as whole milk powder and skimmed milk powder), ingredients must be mixed, and the proportion of ingredients depends on product requirements. The equipment used for batching mainly includes batching cylinder, gouache mixer and heater. According to the requirements of the formula, microorganisms, trace elements and various auxiliary materials are added as ingredients.
3. Homogenization
Homogenization means that the fat and protein in all ingredients and raw milk can be very evenly dispersed in the product through the homogenization process. Homogenization is generally not needed in the production of whole milk powder, whole sweet milk powder and skimmed milk powder, but it is needed if butyl vegetable oil or other immiscible substances are added to the ingredients of milk powder. The pressure during homogenization is generally controlled at 14 ~ 2 1 MPa, and the temperature is appropriately controlled at 60℃. After homogenization, fat globules become smaller, which can effectively prevent fat from floating up and is easy to digest and absorb.
4, sterilization
There are many common sterilization methods for milk. In specific applications, different products can choose appropriate sterilization methods according to their own characteristics. Recently, the most commonly used method is high-temperature short-time sterilization, because the loss of nutrients in milk is small and the physical and chemical characteristics of milk powder are good.
5, vacuum concentration
The sterilized milk is immediately pumped into a vacuum evaporator for decompression (vacuum) concentration to remove most of the water (65%) in the milk, and then put into a drying tower for spray drying, which is beneficial to product quality and cost reduction. Generally, raw milk is required to be concentrated to the original volume of 1/4, and the dry matter of milk reaches about 45%. The temperature of concentrated milk is generally 47 ~ 50℃, and the concentration degree of different products is as follows:
Whole milk powder concentration: 1 1.5 ~ 13 Baume; The corresponding milk solid content; 38%~42%。 Skim milk powder concentration: 20 ~ 22 Baume degrees; Corresponding milk solid content: 35% ~ 40%.
The concentration of fat sweet milk powder is 1.5 ~ 20 Baume degrees, and the corresponding milk solid content is 45% ~ 50%. When producing large granule milk powder, the concentration of concentrated milk will increase.
6, spray drying
Concentrated milk still contains a lot of water and must be spray-dried to get milk powder.
Step 7 cool down
In the equipment without secondary drying, it needs to be cooled to prevent fat separation, and then screened (20 ~ 30 mesh) for packaging. In the equipment with secondary drying, the milk powder is cooled to below 40℃ in a cold bed after secondary drying, and then sent to the milk powder warehouse for packaging through a powder sieve.
Infant milk powder is derived from breast milk, and the selection and determination of this formula is closer to breast milk and closer to the absorption of infants.