4. Drying and powdering
Once the protein has been isolated and concentrated, the time comes to dry it and turn it into a fine powder, or indeed grind it, ready to then be blended, packaged, and distributed. The methods used tend to depend on the protein source and the processing facility or factory – these are typically one of the following:
Spray drying
Spray drying is a rapid dehydration process which uses an atomizer to disperse the liquid into fine droplets, which are then passed briefly through a chamber of hot air. This is generally used for protein powders such as whey (including ours), egg white protein powder or rice protein powder. (9)
Drum drying
Protein powders such as rice protein powder or egg white protein powder can also be drum-dried. In this process, the product is dried over two rotating, high-capacity drums at relatively low temperatures. The sheets of drum-dried product can then be milled into powdered form. (10)
Milling cold-pressed material
Some protein powders, such as those derived from seeds which are cold-pressed in the initial stages to remove the oil (hemp, sunflower, and pumpkin) do not require a drying process. Instead, the dried, pressed material is immediately milled into a fine powder. (11,12)