In the food and food supplement industries, fluid-bed technology is widely used for encapsulation and coating of ingredient particles. Weimar-based Glatt Ingenieurtechnik is offering “solutions for sophisticated applications that require specific particle sizes or shapes, optimum solubility or the protection of active ingredients”.
All fluidised processing systems work on the principle of particle movement in a process chamber with air or nitrogen typically used as the medium for creating a fluidised bed of solid particles. Spray granulation, encapsulation, agglomeration and coating can then be performed by integrating spray nozzles into the chamber.
“For these applications, fluidised bed processing offers the advantage of producing granules or bulk solids in one single process step, including drying, layering and solidification,” explained Katja Oppermann, process engineer with Glatt.
But Glatt can do more with the technology than straightforward coating, encapsulation and granulation applications, and is using these techniques to manipulate ingredient attributes.
“In all our projects we are trying to add value and functionality to an existing product. This is done by physical treatment of products with spray granulation, spray encapsulation, spray agglomeration and spray coating,” said Volker Budzinski, the company’s sales director for food, feed and fine chemicals.
“Examples of how we can enhance particle functionality are through prolonged protection of activity for active raw materials, odour masking, controlled release, overcoming insolubility issues, and many more.”
For example, vitamins and enzymes can be spray granulated and covered with a film coating that enables the controlled release of active ingredients, said Glatt.
Flavours and essential oils can be spray granulated and encapsulated before they receive a protective coating, which makes them stable during transport and storage, and easy to dose.
Agglomerated instant powders that consist of partially hydrophobic components can be formed into readily soluble compounds that don’t separate and offer homogenous particle size distribution profiles.
For particles that are not fluidisable, such as those with sticky properties or non-spherical forms, Glatt uses spouted bed technology.
“Spouted bed is a specialised design of fluidised bed technology with different apparatus constructions and flow configurations of the acting medium,” explained Oppermann.
Other particles that are particularly challenging from a liquid preparation and processing perspective, according to Oppermann, are volatile substances and ingredients that are oxygen-, temperature- and moisture-sensitive.
“To overcome these challenges, the acting fluidised medium can be changed as well as the gas flow management. We can also process liquids at gentle production temperatures (40ºC) so as not to have a detrimental effect on the end product properties,” she said.
As microencapsulation processes start with the preparation of the liquid, Glatt usually supports customers right from the start, in the development of formulations and liquid preparations. It can manufacture the liquid in its technology centre, on a laboratory scale to start with, before testing it in a pilot plant and designing a full industrial scaled production plant.
“Our clients approach us with many different questions. As a solutions provider, we develop and optimise processes, and design individual pieces of equipment or even entire production lines that are ready to use. As an alternative, we also offer contract manufacturing services,” said Budzinski.