Radio frequency biscuit drying claimed to boost output by 30%
Tim Clark, president and general manager of Radio Frequency Co (RFC), told this publication that its Macrowave dryers are placed after the conventional oven and are generally retro-fitted to existing lines, to increase productivity.
The dryer, he explained, removes the drying requirement from the last third of an oven line and enables a hike in the amount of in-spec product throughput per hour.
One biscuit manufacturer, notes Clark, had its output raised to 6,500lbs/hr from 5,000lbs/hr following installation of the RF based dryer.
Flagging up the sustainability of the RF method, he said it is a highly efficient "instant-on, instant-off" form of heating with no energy wasted, as RF energy directly heats only the moisture within food products.
“As water is receptive to RF heating, the RF energy will preferentially heat and dry the product where the moisture content is highest,” he added.
Clark said that as the Macrowave dryer quickly removes residual moisture trapped within the centre of the product, conventional ovens can thus run at the maximum speed, allowing capacity gains and ensuring the product has uniform moisture content.
The dryers, priced from $200,000 up, depending upon the configuration, were developed for high volume biscuit producers with output in the region of 1,500lbs/hr to 10,000lbs/hr.
“In other words [they are not designed] for batch processors or very small specialty manufacturers,” said Clark.
The supplier said that one of Pepperidge Farm’s facilities in the US doubled its Goldfish branded snack cracker line throughput by using the RFC dryer.
Previously, said RFC, the manufacturer could not increase the oven’s throughput dramatically on the cracker as it would significantly increase the amount of moisture in the final product, and would thus negatively impact texture.
As the dryer reduces moisture of the snack cracker in half, without impacting colour, size or other baking characteristics, the Pepperidge Farm plant is able to double production capacity and also extend the Goldfish range, added RFC.
Clark said that off-line dryer systems can be leased for in-plant testing for sensory impact on different products.
RFC works with manufacturers globally and can customise the equipment depending on a particular snack maker’s requirements, added the general manager.