Compiled by / One Fishery
With the rapid development of the aquaculture industry, the global demand for omega-3-rich raw materials is rising, and the supply is becoming increasingly tight.
For this reason, Nofima, a Norwegian food research institute, has developed a new oil that is approved for use in fish feed.
The new oils not only meet the needs of fish for omega-3, but also significantly increase the level of omega-3 in the body after ingestion, improve pigmentation and reduce the appearance of dark spots.
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There are fewer dark spots and the color of the fillets is more attractive
According to the data, about 20 percent of Norwegian salmon is affected by black spots, which costs the Norwegian salmon farming industry hundreds of millions of euros every year.
These dark spots usually refer to dark spots on the salmon body, which are generally no more than 3 cm in size and are mainly located on the front of the fish.
This phenomenon may be a natural physiological manifestation or may be influenced by the environment and diet, and is more prevalent in farmed salmon than in wild salmon.
According to Nofima's report, no harmful compounds have been detected in the dark spots and are safe to eat. However, due to the poor perception and easy to discourage consumers, many seafood processors choose to remove it.
Now, the oil Nofima is looking at, a genetically modified canola oil that can be used in salmon feed, which is expected to reduce the appearance of salmon dark spots.
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A plant that can produce marine omega-3s
Genetically modified canola oil is extracted from a genetically modified canola variety that was developed by Australia's CSIRO in collaboration with Nuseed.
Regular canola oil (left) and fish oil (right)
Therefore, it is rich in omega-3 fatty acids that salmon needs, and people can also get the corresponding nutrients by eating this salmon.
Although it is a genetically improved variety, in the process of extracting oils and fats, only the oil of the raw material is usually extracted, and no genetically modified plant genetic material is carried.
In nature, marine microalgae produce omega-3 fatty acids, which are then eaten by crustaceans and then eaten by fish. As a result, omega-3 fatty acids end up in the fish.
However, it is difficult to obtain such high levels of omega-3 fatty acids in farmed salmon. Therefore, the researchers injected the microalgae gene into the canola seed to produce the same amount of fatty acids.
According to Nofima, GM canola oil has great potential for development. Adding this new type of oil can lead to better health in fish than eating only plant-based omega-3s.
The results of the study showed that the use of omega-3-rich canola oil as fish feed increased the omega-3 content of fish intake, gave the fish flesh a delicate pink color, and reduced the incidence and severity of dark spots in salmon fillets.
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The importance of omega-3s
With the growth of the aquaculture industry, the supply of fish oil in the aquaculture industry is gradually decreasing each year.
In 2000, fish oil accounted for as much as 30% of salmon feed, but by 2020 this proportion had dropped to 10%.
Studies have shown that low levels of omega-3 fatty acids in salmon feed adversely affect salmon growth and meat quality, resulting in thin fish bodies and poor meat color.
Therefore, in order to improve the growth and quality of salmon, the aquaculture industry has begun to gradually increase the content of omega-3 fatty acids in the feed.
The research and development of the fats was funded by the Norwegian Seafood Research Fund in collaboration with the Institute of Oceanography, Australian breeding Nuseed and salmon producer Mowi.
To obtain approval for use, the research team conducted trials at various stages of the salmon life cycle, including freshwater, closed cages and marine cages. At present, the results of the trial are good.