Atlantic salmon is an abundant source of nutrients, known for its rich content of omega-3 fatty acids, particularly EPA and DHA. These essential fats are crucial for heart health, brain function, and overall well-being. But did you know that beyond the prized fillet, valuable treasures hide within salmon?
This new study explores the potential of underutilized parts of Atlantic salmon (viscera, head, and even eggs) as a treasure trove of omega-3! Researchers examined ten different tissues of salmon, including muscle, to see if these ‘by-products’ could be equally beneficial.
A team of researchers from Kangwon National University (South Korea) and the Cold Sea Fisheries Resources Center improved the lipid extraction efficiency from ten tissues of Atlantic salmon (spleen, viscera, gallbladder, heart, pyloric ceca, liver, head, ovary, eggs, and muscle) using low-toxicity solvents, and assessed the nutritional potential of lipids based on their fatty acid (FA) content.
The challenge: separating the good from the bad
Traditionally, fish tissue fatty acid extraction relied on solvents like chloroform. While effective, these solvents pose health and environmental risks. Additionally, separating the fatty acid layer from the solvent proved challenging.
Researchers have discovered a promising alternative: methyl tert-butyl ether (MTBE). This solvent offers several advantages:
- Reduced toxicity: Compared to chloroform, MTBE provides a safer alternative for laboratory personnel and the environment.
- Easier separation: The fatty acid layer floats atop MTBE, simplifying the separation process and minimizing loss.
The study further delved into optimizing the extraction process. By meticulously adjusting the ratio of methanol to MTBE, researchers aimed to maximize omega-3 fatty acid yields. They then used a sophisticated technique called gas chromatography-mass spectrometry (GC-MS) to analyze the fatty acid profile, focusing specifically on EPA and DHA.
Omega-3 champions: eggs and ovaries take the crown
The results were fascinating! While muscle, as expected, contained a good amount of omega-3, the true champions were eggs and ovaries. These tissues exhibited the highest concentrations of EPA and DHA, surpassing muscle by a significant margin.
Unlocking the potential of by-products
But wait, there’s more! Other by-products like liver, viscera, and pyloric ceca also contained significant amounts of omega-3, measuring two to five times more than muscle when measured by total content.
This highlights the interesting potential of often-discarded parts. While the overall omega-3 proportion in total fat content was lower in these by-products compared to muscle, their abundance of these essential fats makes them a valuable source for dietary needs.
Beyond the delicious: rethinking salmon consumption
This research underscores the immense potential of salmon by-products. These often-discarded parts contain a wealth of omega-3, offering a valuable and sustainable source of these health-promoting fats. By extracting omega-3 from salmon by-products through a safer and more efficient method, we can:
- Reduce waste: Transform by-products into valuable resources.
- Sustainable source of Omega-3: Provide a reliable source of these essential nutrients for human health.
While the study focused on Atlantic salmon, the findings could pave the way for exploring similar possibilities in other commercially important fish species.
Salmon by-products: a sustainable and nutritious choice
“In this study, a high yield of FA was obtained using a mixture of ethyl acetate-methanol (10:3, v/v), which can serve as an alternative to previous methods employing MTBE or halogenated solvents like chloroform and dichloromethane,” concluded the researchers.
This study not only sheds light on a more efficient way to extract omega-3 from salmon but also encourages a more holistic approach to consuming this nutritious fish. By incorporating these underutilized parts, we can maximize the nutritional value we obtain from salmon and potentially reduce waste within the fishing industry.
The study was funded by the Leaders in Industry-University Cooperation+ (LINC+) project of the Ministry of Education of Korea.
Contact
Hekap Kim
School of Natural Resources and Environmental Science, Kangwon National University
Chuncheon, Gangwon State 24341, Korea
Email: kimh@kangwon.ac.kr
Reference (open access)
Mai, T. T. H., Choi, J., Park, D., Park, S., & Kim, H. (2024). Evaluation of the nutritional potential of farmed Atlantic salmon (Salmo salar) tissues based on the contents of essential fatty acids. Aquaculture Reports, 36, 102119. https://doi.org/10.1016/j.aqrep.2024.102119
