Generally, dried milk or powdered milk is a manufactured dairy product made from dehydrated liquid milk in various drying processes until it becomes powdered. Drying milk is one way of preserving it. Milk powder has a longer shelf life than liquid milk, which doesn’t need to be refrigerated. Roller drying is the primary method to produce milk powders before spray drying becomes prevalent.
Milk powder manufacturing
Manufacturing of milk powder turned more innovative when milk powder equipment came out, making the milk drying process less effort. Milk powder manufacture is an easy and simple process performed on a large scale. The production may involve gentle removal of water under stringent hygiene conditions while the desirable natural milk properties are retained, such as:
4. Nutritional value
Full cream milk contains approximately 87% water, while skim milk contains about 91% of water. During milk powder production, water is removed through boiling milk under reduced pressure at low temperature milk, sprayed in a fine mist into hot air. It happens to remove extra moisture, forming a powder. About 13kg of WMP or Whole Milk Powder of 9kg SMP or skim milk powder, made from 100 L of whole milk.
Is it a requirement to measure humidity? An optimum dryer performance is attained through monitoring the inlet and outlet flow from the dryer. Air temperature and relative humidity are measured. The temperature and humidity measurement is used to balance the dryer for optimum drying, to reduce the energy cost.
Milk powder production process
Here are the processes in milk powder production:
1. Separation/Standardized. The conventional process for the production of milk powers begins with taking raw milk received at a dairy factory and pasteurizing and separating it into skim milk and cream, with the use of a centrifugal cream separator. If whole milk powder is manufactured, a portion of the cream will be added back to the skim milk, producing milk with standardized fat content. A surplus cream is used in making butter or anhydrous milk fat.
2. Preheating. In preheating, standardizing milk is heated between 75 and 120 °C. The milk is held in a specified time that ranges from a few seconds to several minutes, which is called the pasteurization process. Preheating causes a controlled denaturation of the whey proteins in milk, to perform the following:
1. Destroy bacteria
2. Inactivates enzymes
3. Generates natural antioxidants
4. Imparts heat stability
The exact preheating regime will depend on the product type and intended end-use. Three more processes are next to preheating that is performed in the milk powder equipment.