Spray drying: how liquids become food powders
By Pure Perks ·
Follow the basic spray-drying process and learn what it can—and cannot—tell you about a powdered ingredient or finished food.
Milk powders and some fruit-based powders begin with a liquid feed. Spray drying is one way to turn that feed into small dry particles. Understanding the process helps you ask better questions about a powder without judging it from the word “processed” alone.
The process in a few steps
In a spray dryer, a liquid feed is broken into fine droplets and brought into contact with heated air. Water evaporates as the droplets dry; the resulting particles are separated and collected. Concentration and further drying stages may also form part of the production system. Tetra Pak describes the industrial process in its Dairy Processing Handbook.
The hot-air temperature is not simply the temperature experienced by every part of the food throughout drying. Evaporation and the changing condition of each particle matter. The equipment settings and the feed material must therefore be considered together.
The recipe and settings affect the result
In a study of sweet-orange juice powder, researchers varied inlet air temperature and maltodextrin concentration. These changes affected powder properties and vitamin C retention. The results applied to those materials and experimental conditions; they do not establish a universal retention percentage for every fruit powder. Read the original experiment.
This is also why “spray dried” does not mean “identical to fresh fruit.” To make that comparison, you would need details of the starting material, formulation, processing and the final nutrient composition. A drying-method name supplies only part of that information.
What to ask about a powdered ingredient
- What is the starting material: whole fruit, pulp, juice, milk, or another feed?
- Does the ingredient list identify any added carrier or other ingredient?
- Are nutrition values for the powder or for a specified prepared serving?
- What storage instructions and expiry information apply to the final product?
A general explanation of spray drying is not evidence of a particular brand’s manufacturing method. Supplier or manufacturer documentation is needed before making that claim about a named product.
For related reading, see how to distinguish ingredients from nutrients, our guide to fibre and serving amounts, and the introduction to oats and their different formats.