Green technology uses radio frequency heating to kill flour pathogens

An alternative to carbon producing heating techniques, the firm's macrowave bulk pasteurisation system uses a high frequency electric field to kill microbes.

"The technology is ‘instant-on, instant-off’ using energy only during the treatment process,"​ said the Massachusetts-based firm.

Radio frequency heating, which, as the term suggests, heats materials by radio frequency energy, is deemed to have a green appeal due to the energy savings gained from switching away from carbon sources for heat, as well as bringing savings through diminished energy bills.

A further potential benefit of this growing technology is the fact that radio frequency heat treatment "avoids the deleterious effects on product quality from prolonged exposure to high temperatures", ​claims the US company.

The firm said that in a radio frequency heating system the RF generator creates an alternating electric field between two electrodes.

The material to be heated is conveyed between the electrodes, where an alternating energy field causes polar molecules in the material to continuously reorient themselves to face opposite electrodes, much like the way bar magnets move to face opposite poles in an alternating magnetic field.

"Friction resulting from this molecular movement causes the material to rapidly heat throughout its entire mass,"​ explains the company.

The amount of heat generated in the product is determined by the frequency, the square of the applied voltage, and the dimensions of the material.

Consequently, material to be treated under Radio Frequency's pasteurisation system, that operates at 40 MHz, is conveyed through high-frequency electrode array, "where the depth of penetration and uniformity of heating are optimised, thereby ensuring effective microbe kill ", ​adds the US company.

In addition to flour, other food materials that could use the RF bulk pasteurisation system include pasta, meat and xanthan gum.