SPRAY DRYING

Fluid Air is the future of spray drying and microencapsulation

Spray drying has emerged as a critical innovation for the food and beverage industry and can create efficiency gains in production. Food & Beverage Industry News explains.

Fluid Air is helping define the next generation of spray drying technology by creating scalable powder manufacturing solutions. PolarDry technology utilises electrostatic charge and milder temperatures to achieve conversion, leading to large efficiency gains for a business.

The future of food manufacturing is driven by innovation and high value adding and nutritional, functional, and bioactive ingredients are key to sustainability.

Consequently, the drive for highquality ingredients also requires innovation in manufacturing technologies. PolarDry electrostatic spray drying is a novel technique developed to meet the demands and challenges associated with conventional spray and freeze drying.

Fluid Air, a division of Spraying Systems, has launched the PolarDry commercial range of spray dryers and sales in the US, Europe, Asia and Australia after growing in the years following market launch.

What is PolarDry Electrostatic Spray Drying?

PolarDry electrostatic spray drying is a low-temperature drying technique that combines gas-liquid atomisation and electrostatic charge in a single-step process for conversion of liquid feed to powder.

Since the late 19th century, spray drying technology has seen use on an industrial-scale and the technology has evolved only incrementally with the fundamentals remaining much the same as today.

In both traditional spray drying and in the PolarDry process, liquid droplets are atomised and sprayed into a stream of drying gas.

Then, heat is transferred from the drying gas to the liquid and the solvent is evaporated resulting in a dry, powdered material.

With PolarDry technology, spray drying has advanced to implement an electrical charge at the drying step, and this allows efficient drying at low temperature and improves encapsulation efficiency for lipids and volatile components.

PolarDry takes advantage of electrostatic charge and milder temperatures to create large efficiency gains for producers.

How is Fluid Air revolutionising the process?

Conventional methods of drying are used in food preservation, and spray drying of liquids and encapsulation of oils is common practice in Australian manufacturing.

Although spray drying has many viable applications, it also has limitations, and high temperature processing is the greatest concern.

Many active ingredients are sensitive to heat, often resulting in denaturation, product degradation and loss of quality.

When it comes to drying encapsulated oils, traditional processes yield low retention.

Low temperature drying alternatives exist, and freeze drying is often the preferred solution. Freeze drying overcomes heat-related issues and plays a prominent role in preservation. However, it is a batch process and throughput is limited.

There is a clear need for continuous, non-batch commercial scale drying technologies that maintain a products integrity.

This gap in process capability was recently filled by the PolarDry range of electrostatic spray dryers.

By delivering an electrostatic charge during the atomisation process of liquid droplets, water is evaporated at lower temperatures than possible in traditional spray dryers.

The electrostatic, spray-drying technology is a streamlined, one-step continuous manufacturing process that allows water evaporation at significantly lower processing temperature (<90°C) and, in tandem, enables an agglomeration process to take place before particles are completely dry.

This is done by driving the water or solvent to the outer layer of the atomised droplets and the solids to the core.

This in turn lowers the required evaporation temperature and eliminates active ingredient loss, degradation, or denaturation.

Harnessing the electrostatic effect, non-polar active components can be driven to the core and efficiently microencapsulated, reducing surface active losses, and resulting in greatly increased encapsulation efficiency.

Unlike traditional high-heat spray drying, electrostatic spray drying takes place in an inert gas environment where oxygen is replaced by nitrogen.

This expands applicability to oxygen sensitive materials and not only appeals to anaerobic microorganisms, but it is well suited to spray drying of oxygen-sensitive lipids and other reactive materials.

This technology handles a variety of products ranging from microencapsulated oil emulsions, living microorganisms, bioactive proteins such as lactoferrin and immunoglobulins, other biological materials, and to a lesser degree, inorganic materials.

PolarDry process features: • low operating temperature allows for efficient drying of heat sensitive materials; • greater encapsulation efficiency for lipids and volatile components; • “all-in-one” modular equipment design features a small footprint that reduces maintenance and installation costs; • SAFE - nitrogen inert; • contained, robust processing; • inner liner makes for easy clean-up/ changeover; • process products with low glass transition temperature (Tg); • recycled process gas with negligible emissions virtually eliminates regulatory issues; • complete product line that is scalable from R&D to productionsize models; and • substantially shorter process time than freeze drying. F