Detailed Selling Lead Description
Subject: Radio Frequency defrosting
The drawbacks of conventional defrosting methods can be avoided thanks to the ability of radio frequency (RF) to rapidly generate heat volumetrically within the product. The heating process is fast, uniform and controlled, resulting in a significant reduction of drip losses and minimising product deterioration due to bacterial growth. The RF heating method offers flexibility in the production scheduling and is the ideal solution for many tempering, softening and defrosting processes.
The product is placed on the machine conveyor belt and is transferred continuously through the RF unit (tunnel) passing between upper and lower metallic plates. These plates (also called electrodes) form an electrical capacitor and the product in between the plates becomes the dielectric element of that
capacitor. The electrode plates are connected to a radio frequency generator oscillating at a frequency of several million cycles per second.
When the RF generator applies high frequency alternating voltage between the capacitor plates, the dipolar water molecules of the frozen product will vibrate and rotate attempting to align themselves according to the fast changing opposite plates polarities. This phenomenon causes intermolecular friction, which will turn generate heat rapidly and uniformly within the whole product mass regardless of its size, weight, shape and thermal conductivity.
The amount of heat generated inside the product and the defrosting time are accurately controlled through the voltage applied on the electrode plates and the speed of the conveyor belt
Benefits of the RF defrosting method
Defrosting is achieved in minutes rather than hours/days, even for large product blocks and, if necessary, directly inside packaging used for storage or retail distribution (carton boxes, polyethylene bags, etc.);
The processing speed and uniformity minimise the risk of product degradations (drip losses, deterioration of sensorial, chemical and physical characteristics, bacteria growth, etc.), thus helping to preserve at its best the product quality, especially in the case of heat-sensitive products;
The product can be obtained at the correct temperature needed for the next stage of processing;
Thanks to the high processing speed, radio frequency defrosting can be carried out continuously, with significant logistical advantages in product handling and production scheduling. The production can be organised according to "just-in-time" criteria - a great advantage in the case of sudden orders, last-minute changes in the order or under processing, etc.;
Weather and external ambient conditions do not affect the process, so that it can be controlled accurately and consistently;
Radio frequency equipment requires much less floor space compared to the traditional, large defrosting rooms / equipment; relevant processing costs can also be reduced drastically compared to conventional techniques.