New England Seafood is a major supplier of fresh and frozen premium sustainable fish and seafood in the UK and one of the country’s largest importers of fresh tuna. Its customers are the UK’s leading supermarkets including Marks & Spencer, Sainsbury’s and Waitrose, as well as smaller retail outlets, restaurant chains, food service markets and wholesale sectors nationwide.
AFOS were approached to find an in-house solution to defrosting raw fish, in particular, Tuna. This species of fish has a high market value and is extremely sensitive to defrosting with the slightest miscalculation ruining the fish and causing losses of tens of thousands per batch.
NES source in excess of 30 species of wild and farmed fish and seafood from over 40 countries worldwide and were outsourcing the defrosting process.
Solution
A series of trials were implemented using an AT1/500 defroster with sensors placed directly into the tuna loins linked to a computer controlled system to accurately regulate the defrosting process and meet precise requirements of the customer.
Following successful trials with the smaller defroster the process was scaled up to an AT3/4500 – with a capacity of 4,500 tonnes of frozen fish per defrost cycle.
Tuna loins arrive at NES frozen to -60 degrees centigrade and then are defrosted to between 0 and +4C. Tuna is so sensitive that the flesh can turn white if it comes into contact with metal surfaces while defrosting. The solution also had to take into account that due to varying sizes of Tuna loin, defrosting times would differ.
Core and surface temperature probes were fitted to each of six individual trolleys to ensure differing sizes of tuna loins could be defrosted in one cycle.
When the set point for each trolley is reached the Siemens control unit alarm sounds and the trolley is removed from the defroster.
In order to prevent cooking if the trolley is not removed the defrost cycle stops and a refrigeration unit comes into operation to hold the produce at its set point.
Customer Benefits
The AFOS bespoke solution has enabled NES to take control of its defrosting process resulting in greater efficiency and quality control combined with costs savings and increased yield with each individual loin of fish defrosted perfectly.
The reliability of the AFOS system and the safeguards built into it prevent highly expensive spoilages and enable a seamless flow of fish into the production process.