A leading company in the aquaculture supply chain supplies high-quality frozen fish products used as feed for intensive Atlantic bluefin tuna farming. In this demanding sector consistency, reliability, and controlled processing conditions are essential to ensure efficient downstream operations and optimal feeding performance.
To enhance operational flexibility and processing efficiency, the company sought an advanced solution for defrosting frozen herring or sardine blocks. RF Systems’ radio frequency (RF) technology enabled fast, uniform tempering, improved handling, and precise process control—while fully preserving product integrity.
In aquaculture feed processing, frozen fish blocks must be defrosted quickly and uniformly before operations such as injection or separation. Conventional defrosting methods are often slow, uneven, and labor-intensive, requiring significant space and time. They may also cause surface overheating, excessive drip loss, and reduced product quality.
The company needed a solution capable of defrosting large frozen herring or sardine blocks, each weighing approximately 21 kg and packed in paper bags first and then in cardboard boxes. The fish blocks had to reach the final controlled temperature starting from an initial temperature of about −18 °C. Key requirements included uniform temperature throughout the block, easy separation of each fish, minimal water and weight loss, high and predictable hourly throughput, and compatibility with continuous industrial processing.
RF Systems supplied a continuous radio frequency defrosting solution operating at 27.12 MHz. RF energy generates heat directly inside the product by acting selectively on its water content, enabling fast and uniform tempering regardless of product size, geometry, or packaging. These featurues avoid surface overheating and temperature gradients typical of conventional defrosting methods.
THERIO, the RF Systems’ equipment type designed for defrosting applications, has been chosen by the company that appreciated its features: up to 75 kW RF power with water-cooled generator, PLC for automatic control of RF field intensity, adjustable electrode system for precise energy delivery, continuous conveyorised operation and a compact footprint. The machine is designed for the continuous tempering/defrosting of frozen herrings in cardboard packaging, with a maximum throughput of 1.400 kg/h.
Various RF power levels and electrode set up were applied to achieve optimal defrosting uniformity, throughput, and to separate the fish easily. The RF treatment by THERIO consistently produced final product temperatures between −4 °C and −1 °C, ideal for subsequent injection and handling phases.
The adoption of RF defrosting brought clear advantages: uniform defrosting throughout the block, easy manual separation of herrings and sardines, negligible drip loss, no observable product degradation, significantly reduced processing times, and improved production flexibility for just-in-time operation.
By implementing radio frequency defrosting technology, the customer significantly improved efficiency, product quality, and operational flexibility. The RF Systems solution proven to be reliable, scalable, and fully compatible with demanding industrial aquaculture feed applications, offering a robust and modern alternative to conventional defrosting methods.
