Spray Drying vs Natural Dehydration: What Food Manufacturers Need to Know

What is Spray Drying?

Spray drying is an industrial process used to convert a liquid or slurry into a dry powder. The process works by atomising a liquid extract into a fine mist and exposing it to a stream of hot gas — typically air heated to between 150°C and 250°C. The moisture evaporates almost instantly, leaving behind fine dry particles that settle at the bottom of the chamber.

Spray drying is widely used in the production of instant coffee, dairy powders (milk powder, whey protein), pharmaceutical ingredients, and certain food flavourings. It's a fast, high-volume process that works well when the starting material is a liquid extract or slurry.

However, spray drying comes with a significant limitation when applied to food ingredients: the fine powder produced tends to be extremely hygroscopic — it absorbs moisture from the air rapidly and clumps together, making it impossible to handle, pack, or use in manufacturing. To solve this, processors must add a carrier agent — and the most commonly used carrier is maltodextrin.

What is Natural Hot-Air Dehydration?

Natural hot-air dehydration is a fundamentally different process. Instead of starting with a liquid extract, it starts with the whole, fresh ingredient — onions, garlic, turmeric, moringa, beetroot, hibiscus, and so on. The produce is cleaned, sliced or ground as appropriate, and then passed through a temperature-controlled hot-air tunnel or tray dryer. The airflow progressively removes moisture from the product until the moisture content drops to below 6%, at which point the product is shelf-stable.

The result is a pure, dried version of the original ingredient. No carrier agents are needed because the fibre, structure, and dry matter of the whole vegetable or fruit provide the physical bulk that holds the powder together. Onion powder produced this way is just onion — nothing else. Moringa powder is just moringa leaves, dried and milled.

This process is used by Atlas AgroFood for our entire range, from dehydrated onion powder and garlic powder to turmeric powder and moringa powder.

Why Spray-Dried Powders Contain Maltodextrin

This is the core issue that clean-label food manufacturers need to understand. When a liquid ingredient — say, an onion extract or a fruit juice concentrate — is spray-dried, the resulting powder is so fine and hygroscopic that it cannot function as a usable product without a carrier. Without maltodextrin (or a similar carrier such as acacia gum or modified starch), the powder sticks to the spray-drying chamber walls, clumps during storage, and cannot be packed, measured, or used in manufacturing.

So maltodextrin is added — typically at a ratio of 20% to 60% by total weight. This means that a product labelled "onion powder" or "tomato powder" may contain anywhere from one-fifth to three-fifths maltodextrin by weight. The actual vegetable content is diluted accordingly, and so is the colour, flavour intensity, and nutritional value.

For a food manufacturer who wants to declare a simple, single-ingredient label — "Ingredient: Onion Powder" — the presence of maltodextrin forces a more complex declaration: "Onion Powder (Onion, Maltodextrin)". For brands positioned on clean-label values, this is a significant problem.

Side-by-Side Comparison

The table below captures the key differences between the two processing methods for food manufacturers evaluating ingredient options:

Which is Better for Clean-Label Applications?

If your product's label reads "Ingredient: Onion Powder," consumers rightfully expect that product to contain nothing but dried onion. Naturally dehydrated onion powder delivers exactly that. Spray-dried onion powder — almost always — does not.

The clean-label movement is not a passing trend. Regulatory bodies in the European Union, the US, and increasingly in Asia are tightening definitions around "natural" labelling. Consumer demand for shorter ingredient lists and recognisable ingredients has fundamentally shifted how food brands need to think about their supply chain.

If you're building a product that depends on a clean-label positioning — whether it's an organic seasoning blend, a premium soup mix, a functional health supplement, or a baby food — naturally dehydrated ingredients are the only sensible choice. The extra diligence required to find suppliers who genuinely use hot-air dehydration (rather than spray-drying and re-labelling the powder) is worth it. Learn more about our approach on the Atlas AgroFood Clean Label page.

Applications Where Natural Dehydration Excels

Naturally dehydrated ingredients are the preferred choice across a wide range of food manufacturing applications where purity, flavour integrity, and clean-label status are non-negotiable:

• Soup mixes and bouillon: Dehydrated vegetable pieces and powders that reconstitute cleanly, with authentic colour and flavour.
• Instant noodle seasoning sachets: Onion flakes, spring onion, carrot, and garlic that rehydrate properly in hot water.
• Seasoning blends and dry rubs: Precise flavour delivery without the diluting effect of maltodextrin.
• Health supplements and nutraceuticals: Where the consumer is paying for the active ingredient, not a carrier agent.
• Baby food and infant nutrition: Where absolute purity and minimal processing are essential.
• Premium ready meals and meal kits: Where the ingredient panel is a selling point, not a compromise.

Atlas AgroFood's range covers all the staple dehydrated ingredients used in these applications — including onion powder and flakes, garlic powder, and turmeric powder — all 100% additive-free and produced without spray-drying.