Food Powders with High Functionality: Technologies and Trends

Granulation and agglomeration are two central processes in powder refinement that differ in terms of the aggregate state of the initial material and the resulting particle properties. In spray agglomeration, one or more fine-grained powders are combined with a binder to create a porous "raspberry structure" (see Fig. 1). The choice of binder must be compatible with both the product and the application, for example in terms of fat content or declaration. Dr Georg Fröhlich, Sales Manager at Glatt Ingenieurtechnik GmbH, emphasised that water and organic binders such as hydrocolloids, caseins, gum arabic or sugar are usually used for foodstuffs. The result is easily wettable, porous agglomerates with good solubility and improved flow behaviour, which impress with a reduced dust content and minimised segregation effects.

In contrast, spray granulation requires a liquid as the initial material. A compact "onion structure" is created (see Fig. 2) by spraying layers of liquid onto particles in succession and drying them. This enables targeted adjustment of product properties such as particle size and bulk density. Due to their round, uniform shape, granulates are ideal for subsequent coating processes. They are also characterised by a high particle hardness and density, which reduces the transport volume and hygroscopicity.

Agglomerates are more fragile, easily dispersible in liquids and ideal for compressed products such as tablets. Granulates, on the other hand, impress with their low dust content, high flowability and precise machine dosing, explains Frank Hellerung, Head of Sales at SternMaid GmbH, Contract Manufacturing Services in Wittenburg, Germany.

The requirements for powder products go beyond the correct physical properties: Many products consist of sensitive ingredients such as flavourings, vitamins or probiotics. Fluidised bed technology is an efficient powder refinement process in which particles are swirled up by a stream of air, evenly sprayed with a liquid and then dried. This results in coated or encapsulated particles. This technology makes it possible to protect sensitive ingredients (such as enzymes or omega-3 fatty acids) from moisture, oxygen or light. The ingredients can be efficiently encapsulated (by micro-encapsulation) and coated (the coating) to ensure a controlled, pH-based or time-controlled (immediate or delayed) release, emphasised Frank Hellerung.

During coating, particles are fluidised in the fluidised bed, evenly coated with a film and dried. Particles coated in this way offer the possibility of protecting sensitive ingredients from environmental influences. One example is the application of fat layers to spice powders to protect flavours during cold storage and then release them during baking, explained Dr Georg Fröhlich.

During encapsulation, sensitive ingredients such as omega-3 fatty acids and beta-carotene are enclosed in a matrix. If the spray granulation process is selected for drying this matrix, micro-granules are produced which offer additional protection and release control of the ingredients thanks to their compact structure. Coating and micro-encapsulation play a central role in making sensitive ingredients preservable, storable and available and are often used for food supplements. However, they are generally not used with fats but, for example, instead with hydrocolloids, sugar derivatives or high-quality polymer coatings, added Frank Hellerung.

Powder production in the food industry increasingly relies on sustainable and efficient approaches in order to fulfil both ecological and economic requirements. Energy-efficient processes, such as heat recovery during spray drying, and the reduction of waste through dust agglomeration help to conserve resources. At the same time, packaging optimisation enables transport costs to be reduced thanks to higher bulk density. Last but not least, according to Frank Hellerung from SternMaid, powder products also help to reduce water transport, as they require less liquid due to their longer shelf life and better processability.

Leading companies such as Glatt Ingenieurtechnik GmbH and SternMaid GmbH are advancing these sustainable developments with innovative approaches.

Glatt Ingenieurtechnik GmbH focuses on energy-efficient lines with heat recovery, the utilisation of by-products through dust agglomeration and the reduction of packaging size thanks to higher bulk density. In addition, improved solubility enables faster processing, as Dr Georg Fröhlich emphasised.

SternMaid GmbH, part of the Stern-Wywiol Group, also pursues a holistic approach to sustainability. Since 2023, the company has been integrating strategically centralised sustainability measures into all business processes, supported by Corporate Sustainability and local ambassadors. Long-term goals are set with new structures and a materiality analysis in accordance with the Corporate Sustainability Reporting Directive (CSRD). SternMaid already focusses on recyclable packaging and the use of renewable, high-quality raw materials, added Frank Hellerung.

Future developments will focus on improving the solubility of animal and plant proteins, utilising by-products to conserve resources and producing dust-free products for safe processing. The integration of recyclable packaging technologies is also becoming increasingly important. These measures and the continuous optimisation of established processes strengthen the competitiveness of manufacturers and meet the growing demands of consumers for sustainable products.

In summary, it can be said that powder refinement plays a key role in the food industry. It enables the production of high-quality products that meet the demands of consumers and processors alike. The experts agree that the properties of powders must be adapted to the respective applications.

Dr. Georg Fröhlich
Sales Manager – Process Technology Food, Feed & Fine Chemicals
Georg.Froehlich@glatt.com
Glatt Ingenieurtechnik GmbH
Nordstr. 12, 99427 Weimar, Germany

Frank Hellerung
Head of Sales
fhellerung@stern-wywiol-gruppe.de
SternMaid GmbH & Co. KG, Contract Manufacturing Services
Am Mühlenberg 4, 19243 Wittenburg, Germany