The deep-freezing process
After being caught in the wild, the product is sorted, cleaned, and gutted (depending on the final format) and taken to the freezing tunnels or cabinets as quickly as possible.
A BORDO
EN TIERRA
Freezing is carried out at temperatures typically between −40°C and −30°C for a period of between 2 and 8 hours, depending on the species, volume, and equipment. The process is not considered complete until the center of the product reaches −18°C or below.
Once deep-frozen, the product is stored in a cold room and kept at a temperature of approximately −25°C until unloading.
Chain of custody
Maintain the cold chain to the point of sale
The chain of custody defines controls to maintain the cold chain and traceability during the post-unloading phases: storage, packaging, and marketing.
This helps to preserve the storage conditions of the certified product and prevent incidents that could affect its quality.
Fishing operations
HYGIENE, TRACEABILITY, AND LABELING
Operations are subject to food hygiene and safety regulations, as well as traceability and labeling requirements. At WFAS, certified vessels must comply with applicable regulations and maintain the corresponding documentary evidence.
Freezing process
PRODUCT HANDLING, CLEANING, AND FREEZING
To preserve the quality of fish and seafood, it is essential to quickly reduce the temperature after capture. Rapid freezing helps to limit physical, chemical, and microbiological changes and maintain sensory properties.
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To prevent fish from spoiling, we must therefore take care when handling the product, cleaning it, and freezing it as quickly as possible. Deep-freezing using modern, fast, and efficient cooling systems guarantees the high quality and freshness of the final product, as the fish is deep-frozen within a short period of between 2 and 8 hours, meeting the highest standards for preserving the organoleptic and nutritional properties of our fish products.
The freezing process therefore begins shortly after the fish has been taken out of the sea and is carried out using freezing tunnels or plates. In both cases, the fish is deep-frozen, but depending on the system, the process takes more or less time.
5.2.1 Freezing tunnels (cold air).
Refrigeration equipment system suitable for freezing caught fish and storing it in holds.
These are insulated chambers in which the product to be frozen is placed, and a stream of cold air is circulated to extract heat from it.
Main characteristics:
The product is only in contact with the air, so it does not suffer any deterioration, except for a small amount of drying, which speeds up the freezing process. This can cause a slight loss of weight, which can be avoided if the product is frozen wrapped or packaged, in which case the loss will be negligible.
It adapts to any shape and size, making it very suitable for whole fish.
They tend to have high energy consumption requirements.
There are continuous and stationary tunnels. In the former, the product moves through the tunnel and they are not very common in fishing. Stationary tunnels are the most commonly used and the fish is usually placed on racks or trays.
The fish caught must enter the tunnels at a temperature of 15 ºC and a final temperature of -18 ºC will be achieved. The tunnels work thanks to a refrigerant and forced air circulation. They have a specific capacity in kilograms per freezing cycle, which varies depending on the model, giving them a total freezing capacity for each working day. Each freezing cycle will take approximately 7 hours until the desired temperature is reached.
5.2.2 Plate cabinets (direct contact).
Refrigeration equipment system suitable for freezing caught fish and storing it in holds, using direct contact with the fish to freeze it.
A plate freezer cabinet works by transferring heat from the product to refrigerated metal plates that are in contact with it. The heat is transferred by conduction, which improves the performance of the installation and reduces freezing time.
The plates are made of extruded aluminum and refrigerant circulates inside them. There may be a hydraulic system to apply pressure to the plates and thus ensure contact during freezing.
There are two types of plate freezer cabinets: horizontal and vertical. Horizontal cabinets are typically used for small fish or fillets, while vertical cabinets are used for large fish.
The capacity of the cabinet is variable and they usually have an estimated freezing time of 120 minutes. This rapid decrease in the temperature of the fish means that a large number of freezing cycles can be carried out each fishing day.
The fish caught usually enters the tunnels at a temperature of 15 ºC and a final temperature of -18 ºC is achieved.
5.2.3 Storage in holds (operating temperature).
After freezing, the fish caught will be stored in the holds. The fish enters at a temperature of -18 °C and will be kept at an operating temperature of -25 °C.
In order to achieve greater energy efficiency, it is advisable for the refrigeration system to be divided into two completely independent circuits, one for freezing, consisting of the freezing tunnels and cabinets, and another circuit consisting of the hold and the tween deck.
These refrigeration facilities are regulated by Royal Decree 138/2011, of February 4, which approves the Safety Regulations for Refrigeration Facilities and their complementary technical instructions.
5.2.4 Records (Temperature Control Plan / Cold Chain Log / HACCP).
Ships must include in their Hazard Analysis and Critical Control Points (HACCP) Manual, among other prerequisites, the “Temperature Control Plan,” which covers all refrigeration equipment used in the production and storage process. A visual inspection and temperature recording shall be carried out daily and noted in the ship’s corresponding Cold Chain Log.
Description of the standard
TIME AND TEMPERATURE
The key factors for frozen product quality are TIME and TEMPERATURE. The process must be carried out in the shortest time possible, taking care of:
- Freshness and condition of the product.
- Correct handling and processing.
- Temperature control and verification.
Processing and washing
EVISCERATION AND DEHEADING OF EACH PIECE
Once on board, the catch is processed according to the final format (whole or gutted/headed). Before freezing, the product must be completely clean, and a visual inspection is carried out to check for possible parasites.
Freezing process
TEMPERATURE BETWEEN -40°C AND -30°C
After processing and washing, the product is transferred to freezing equipment at temperatures between −40°C and −30°C for a period ranging from 2 to 8 hours, depending on the species, volume, type of processing, and equipment capacity.
Quick freezing is not considered complete until the center of the product reaches −18°C or below. Thermographic checks and manual controls are carried out to monitor this process.
In some cases, the product is glazed after freezing (outer layer of ice) as protection during storage.
