Fish Oil, a valuable product rich in omega-3 polyunsaturated fatty acids (EPA and DHA), vitamins A and D, is extracted from the tissues of fatty fish species. The process of obtaining it has evolved over time — from primitive rendering on ships to high-tech methods ensuring purity and preservation of beneficial substances. Modern production is a complex multistage process, strictly controlled at each stage.

Historical method: rendering from cod liver

Traditionally, for centuries, fish oil was primarily obtained from cod liver. This method, known as the "liver" method, involved the natural separation of fat. Freshly caught cod was left in large barrels, where, under the influence of solar heat, fat gradually rose to the surface. It was simply collected and filtered. A more technologically advanced approach involved rendering: the liver was ground and steamed in special boilers. Under the influence of temperature, fat melted and separated from the protein mass. The obtained raw material was rich in vitamins but could have a specific smell and taste, as well as contain impurities. It was this "liver" fat that was known to Soviet children as an obligatory food supplement.

Modern industrial method: using fish bodies

Today, the main volume of fish oil is produced not from the liver, but from the bodies of fatty fish species such as anchovies, sardines, mackerel, and herring. This is so-called "fish" oil. This approach is more sustainable and allows for greater production. The process starts with the preparation of fish meal. Fresh raw material is delivered to processing plants, where it is first boiled in large boilers for protein coagulation and separation of the liquid fraction. The obtained mass is pressed to remove most of the water and fat. The solid residue goes into fish meal production, while the liquid fraction, containing water, proteins, and fat, undergoes the next key stage.

Centrifugation and purification: separation of fractions

The liquid mixture obtained after boiling and pressing is directed to high-speed industrial centrifuges. Under the action of centrifugal force, it is separated into three main fractions: light fish oil, which is collected in the center, water fraction (so-called "stickwater"), and heavy sludge containing protein residues. The separated crude oil still contains some amount of moisture, impurities, and free fatty acids. To remove them, it is washed with hot water and subjected to refining. The refining process may include neutralization, bleaching, and deodorization, resulting in a clean, transparent, and odorless product.

Quality preservation technologies: molecular distillation

The most advanced method used for the production of high-quality food supplements and pharmaceutical preparations is molecular distillation. This is a process that takes place under deep vacuum, allowing for the separation of substances with different molecular weights at significantly lower temperatures than in normal distillation. This is critically important for preserving thermosensitive omega-3 acids, which are destroyed by intense heating. Molecular distillation effectively removes potential contaminants such as heavy metals (mercury, lead), dioxins, and polychlorinated biphenyls that can accumulate in fish tissues. As a result, a highly purified omega-3 concentrate is obtained, which is used in capsules and pharmaceutical forms.

Thus, modern fish oil extraction is not just simple rendering, but a sophisticated technological chain aimed at maximum extraction of beneficial components, their purification from harmful substances, and preservation of the biological value of the final product. From the raw, vitamin-rich liver fat of the past, humanity has moved on to the production of safe and standardized concentrates that meet the strict requirements of modern medicine and dietetics.

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