Nonfat milk powder is made by removing water from pasteurized skim milk.
Here's a breakdown of the process:
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Skim Milk Preparation: The process begins with fresh milk that has had the fat removed, leaving skim milk.
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Pasteurization: The skim milk is then pasteurized to kill harmful bacteria. This usually involves heating the milk to a specific temperature for a set time.
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Concentration: The pasteurized skim milk is then concentrated to reduce the water content. This can be done through:
- Evaporation: The milk is heated under a vacuum to evaporate a significant portion of the water. This results in a concentrated milk solution.
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Drying: The concentrated milk is then dried to a powder form using one of two primary methods:
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Spray Drying: This is the most common method. The concentrated milk is sprayed as a fine mist into a hot air chamber. The hot air rapidly evaporates the remaining water, leaving behind fine particles of nonfat milk powder. These particles are then collected.
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Drum Drying: The concentrated milk is applied as a thin layer onto heated rotating drums. The water evaporates as the drums rotate, leaving a thin layer of dried milk solids, which are then scraped off as flakes and ground into a powder.
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Sifting and Cooling: The powder is then sifted to ensure uniform particle size and cooled to prevent clumping.
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Packaging: Finally, the nonfat milk powder is packaged in airtight containers to protect it from moisture and maintain its quality.
The final product, nonfat dry milk (NDM), contains no more than 1.50% fat and no more than 5.0% total moisture, complying with regulations set by the U.S. Federal Food, Drug, and Cosmetic Act. This process ensures a shelf-stable and versatile product.
