Processors can avail of testing using novel drying method

By Jane Byrne

- Last updated on GMT

Related tags Food

European processors can now test their products on equipment that employs a novel technique using light refraction to dry foods, claims the US manufacturer.

MCD Technologies said that a key feature of its concentration and dehydration technology is its ability to preserve a product’s beneficial properties, including its nutrition, flavour, colour and aroma through its gentle approach to drying.


The company explained that its Refractance Window (RW) process involves a slurry of liquid product being applied evenly to the top surface of a continuous sheet of impermeable, transparent plastic, which floats on hot water; infrared energy then passes from the water to the slurry at the speed of light.

“The infrared energy and conducted heat employed by RW drying deliver rapid drying at atmospheric pressure rather than under a vacuum, and also inhibits oxidation of the product due to the reduced surface area that results,”​ said Karin Bolland-Magoon, president MCD Technologies,

She told that the company is expanding into other markets and is currently working with a European based food ingredient manufacture to enhance its drying processes.

Testing facility

Bolland-Magoon encourages European manufacturers to send their products to the company’s Washington state-based processing facility where large and small scale testing on foods can be undertaken prior to any commitment on the part of the manufacturer to purchase the equipment.

She said the RW method of drying can be used with a wide range of food and beverage products including fruit, vegetables, eggs, cocoa mix, tea, coffee, meat, fish and poultry.

“The US navy has used our technique to dry eggs and found the rehydrated version was indistinguishable from fresh eggs,” ​claims Bolland-Magoon.

According to Bolland-Magoon, the company received a grant in 1998 from Washington Technology Center to work with Washington State University to document qualitative aspects of RW drying.

“Work done to date has demonstrated that RW dried strawberry retains more Vitamin C than freeze-drying and similar levels of Vitamin A,”​ she said.

Low environmental impact

Bolland-Magoon claims the RW technique outscores conventional freeze and spray drying techniques not only in terms of nutritional quality of food post process, but also in terms of the net savings to the end user with regard to initial equipment cost and reduced environmental impact.

“In comparison to spray drying, our technique does not generate any dust, while its low water use saves resources and mitigates pollution​,” she said.

Bolland-Magoon said that the RW drying technique enables simple, fast and continuous operation, while eliminating the need for pre-processing for many products, and that most products dry in two to four minutes, using the process.

She added that the dryer is easily cleaned by simply removing and washing certain components and by washing others in place.

Related topics R&D