Preparation process
Contenido
El proceso comienza de madrugada en las lonjas locales. Una vez realizadas las compras de pescado, las materias primas son trasladadas inmediatamente a la factoría, con lo cual se mantienen intactas sus propiedades alimentarias. Las condiciones en las que llegue el pescado influirán de forma decisiva en la calidad del producto final.
Reception
This is the stage of the process in which the raw materials are received at the factories. At this stage we must control the following factors:
It is very important to code the raw materials to which a batch number is assigned, through which we can know the history of that fish at any time.
Weighing is also a very important task. With this weight we will know the performance obtained with each unit, an important fact since it will allow us to know which raw materials are most interesting to buy, based on the results obtained. For example, with Mackerel (Scomber Scobrus), from each kilo of raw fish we will obtain 300 grams of useful fish for canning, then we will obtain a yield of 30%. Depending on the size and the fishing season, different results can be achieved.
The manufacturing process of canned fish begins with the reception of the different raw materials from the different markets. This raw material is subjected to a series of treatments before packaging. They basically consist of washing, heading, cooking, chopping or filleting.
Washing
All fish that are going to be processed will require washing, as well as a visual observation for the presence of various species or foreign matter (such as bacteria, parasites or other types of foreign matter that are more difficult to detect).
Headless
We will observe the jugular area of the decapitated fish. The heading will be carried out using clean and straight cuts, without crushing or bruising the meat, the surface of the cut must be free of roughness. If the cuts produce tears in the meat, these encourage the entry of microorganisms present on the surface into the muscle.
Cooking
In this phase, measuring the cooking time, measuring the temperature of the steam or cooking water, measuring the temperature of the central spine, visual observation and the texture of the meat are very important.
Once cleaned and deheaded, the fish is manually placed on the grills to be cooked at 100°C in brine or steamed. Cooking the fish is one of the most important parts in the manufacturing process, there is no estimated time, it always depends on the size and fat of the fish, then it will depend on the origin and fishing season.
Indicating cooking times is a very delicate task; overcooking leaves the fish dry and not very juicy, as well as a loss of yield. If the fish is undercooked, the yield will also decrease because the fish falls apart in the hands of the operators, and will have a high percentage of water.
To verify cooking, two methods are used, in both we remove a piece of the cooking basin. Once the piece is obtained, we can either observe the firmness and structure of the meat, or divide the fish into two parts and take the central bone of the fish, break the bone and observe if the tendon inside the central spine breaks or stretches like a rubber band. If it breaks, it would mean that the fish is not yet perfectly cooked and requires more time.
Filleted
In this phase we must eliminate all remains of spines, viscera, skin and blood, as well as darkened areas. The cuts must be made longitudinally to the body of the fish, clean cuts, without tears and without bones from the abdominal cavity in small species.
As already mentioned, once the fish has been cooked, it is handed over to the team of people in charge of scraping and filleting who will obtain four clean fillets from one piece of cooked fish. In this process the fillets are carefully cleaned, removing all bones and skin.
All fillets are weighed and by comparing with the gross kilos we can obtain the yield per manufactured batch. Each operator's fillets are weighed in order to encourage those who obtain more kilos. The productivity tables are changed depending on the size and quality of the fish; the smaller the fish, the fewer kilos of fillets the operator has to obtain. Operators are individually informed every hour of their productivity.
Packaging
Small fish must be packaged in one whole piece, the size of the pieces in a container must be as homogeneous as possible, the number of pieces per container within the same batch must be similar. For tuna packaged in a log or block, there must be enough space to receive the covering liquid.
Once the fillets are obtained, we begin to trim them manually. They will then be selected and placed in cans or glass containers, after ensuring that
the fish is properly packaged.
Adding the cover liquid
In this phase, we prepare to fill the container with the covering liquid, which depending on the case will be olive oil, vegetable oil, tomato, or pickle. The covering liquid must range between 35% and 10% of the capacity of the container, depending on the product, form of presentation, dimensions of the container and what is indicated on the label. The tomato is obtained by making a mixture with tomato, water, oil and salt. We make the pickle by mixing vinegar, water and salt.
Closed and washed
The airtightness of the empty can must be checked at the beginning of the day and whenever any parameter of the seaming machine is modified, injecting pressurized air, up to permanent deformation (or over 2.5 kg/cm), with the container submerged in water.
With the liquid already in the cans, they are closed hermetically and washed to achieve good conservation. The non-recontamination of the final product, from its manufacturing to its consumption, is necessary for a preserved product to be defined as such, and therefore as a non-perishable product. Therefore, the hermetic closure of the container is an essential factor to control. The most common container for canned fish is metal (tin or aluminum).
Heat treatment and cooling
Finally, sterilization proceeds, through which the cans are placed in the Autoclave where they will be subjected to high temperatures for a time that varies depending on the type of product. For any canned food to be absolutely safe, it is a necessary condition that the product has been subjected to sufficient heat treatment to eliminate all pathogenic microorganisms and their resistant forms. The best known of these, and which is taken as a reference, is Clostridium botulinum. The filling and closing of containers must be continuous, with sterilization carried out immediately after completing the number of containers necessary to load the autoclave. The time from when the first container was closed until sterilization begins must be less than one hour. Under no circumstances should containers be left untreated at the end of the day. All containers loaded into an autoclave must be of the same dimensions and with the same product and covering liquid. It could be accepted in different baskets or in different products as long as the process was identical. Cooling must be very rapid, reaching 40 °C in the center of the container in less than 10 minutes (depending on the size of the container). It means reducing the interior temperature of the autoclave by 1 to 2 minutes. The cooling water must be chlorinated and clean, potable water must always be used, both when cooling the autoclave and in the subsequent baths of the containers.
Once sterilized and cooled, the cans are cleaned, marked with a batch number, boxed, labeled, thus becoming ready for consumption.
Labeled
The minimum content of the labeling will be: Name of the product, form of presentation, net and drained weights, normalized capacity of the container, list of ingredients, identification of the manufacturer and best before date.
Storage
The storage location must be clean and dry, the packaging must be of such a size that it prevents the movement of the packaging. Packaging should be stacked in cages or at a reduced height to avoid crushing. All handling of packaging must be careful, in order to avoid knocks, which could dent the containers, affecting their seams and edges, compromising their airtightness, in addition to detracting from their appearance.