The canning process for canned fish includes several key steps:
- Can Manufacturing: Cans are manufactured from tinplate or aluminum. The necks of the cans are formed and inner coatings are applied to protect the contents from corrosion and preserve their quality.
- Decoration: Cans are decorated and varnished, both outside and inside, to protect them and ensure their mobility in the process and on the filling line. After decoration, the cans are cured in ovens to dry and stabilize the printing.
- Filling: Products such as meatballs or fish cakes are manually placed in the containers, which are then filled to the top with brine or sauce.
- Sealing: Cans are hermetically sealed with code-marked lids to ensure product traceability.
- Sterilization: Closed cans are heat treated in autoclaves to achieve complete sterilization. The temperature and treatment time depend on the size of the can and the nature of the heat transfer to the product.
- Cooling: After sterilization, the cans are rapidly cooled to avoid reactivation of thermophilic microorganism spores.
- Storage: The cans are stored in cool, dry places, free from animals and rodents, protected from heat and light to preserve the quality of the product.
It is important to emphasize that throughout the process it is essential to follow good manufacturing practices and maintain constant training of workers in these practices to ensure the safety and quality of the final product. In addition, consumers are advised to verify the production date, expiration date, and sanitary approval before consumption. Canned fish provide high nutritional value, including protein and essential fatty acids such as omega-3, EPA and DHA.
The precooking of fish prior to canning may vary depending on the type of product and the specific process being used. In some cases, the fish is subjected to a steam pre-cooking process, while in others a drying process may be used instead of steaming, especially if certain qualities of the fish such as its soft and delicate texture are to be preserved.
For example, ordinary precooking with steam can result in the loss of substances that the fish must retain to maintain an adequate texture. It is also suggested that for certain types of fish, such as those with a more fibrous muscle structure, the loss of fats and soluble proteins that soften the product should be avoided, which could imply the use of drying methods instead of steaming.
In summary, although steaming is a common precooking method in the canning industry, it is not the only method and its use may depend on the specific characteristics of the fish and the desired result in the final product.