Wild-Indag Process Technology in Germany said it has built a prototype machine combining ohmic heating with microwave and radio-frequency techniques, which have so far only been applied alternatively to heat foods.
The Indag High Power Heating System (IPS) combines the best qualities of the two processes while eliminating the downsides, the company claimed.
The prototype of an IPS-plant reaches an output of up to three tons of foodstuffs per hour with peak temperatures of up to 140°C within 90 seconds. The company presented the IPS technology for the first time at the Anuga FoodTec exhibition held earlier this month in Cologne.
Manufacturers mainly carry out heating via steam or heating water in double-jacketed tanks. With this method, the heating medium has to heat up the tank first, before the temperature is transferred to the product. Since the heating step takes so long, the product characteristics, such as colour, taste, and smell are impaired, Wild-Indag stated.
The product has to be constantly stirred in order to keep it from sticking to the over-heated tank wall or from scorching.
Ohmic heating provides a quicker method of heating of foodstuffs with the help of an electric current. Ohmic heating uses electrodes in direct contact with food.
However, the required temperature in the core of chunky products such as fruit, vegetables, or meat is reached only after a comparably long time of impact.
In addition, electrolytic decomposition products of the electrodes are released into the finished product.
Microwave and radio frequency heating technology can directly heat chunky products without contact having to be made. The method by itself can lead to partial over-heating, leading to a loss in quality.
The IPS heating method allows liquid parts of the product to be heated almost immediately via current. The chunks in the product are heated very quickly via radio frequency.
"The short-term heating to the very core guarantees that the product characteristics such as colour and taste are preserved in an unprecedented quality," the company claimed. "In addition, undesired reaction products of the electrolysis are kept from being transferred into the product."
The company has built a complete procedural plant with integrated IPS heater at its manufacturing facility in Heidelberg. The plant is available for customers to carry out heating tests.