There has been increased interest in the health benefit of eating fish and fish products, including salmon. The health benefits of eating salmon are related to the amount of lipid (fat) and omega-3 fatty acids in these fish. Research on the health benefits of fish has focused on eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are omega -3 fatty acids that have important heart benefits such as reducing blood cholesterol, triglyceride levels and inhibit blood platelet formation and clotting. The ratio of omega-3/omega-6 fatty acids is also important with higher ratios being desirable for physiological functions in humans. Omega-6 fatty acids are essential, but excessive amounts can be harmful. There is general agreement among researchers that the lipid content of seafood that is high in omega-3 fatty acids provides numerous health benefits for humans.

 

The objective of this study was to determine the differences in lipid content and fatty acid composition of three types of Chinook salmon with different flesh colorations. Although most Chinook salmon are red fleshed in color, there are runs of Chinook salmon that exhibit other flesh colors and are harvested in the ocean troll fishery off the coast of Washington. The flesh colorations include a white-fleshed salmon (Pearl), a mottled-fleshed salmon (Marbled) and a red-fleshed salmon (Red). This study was conducted on ocean harvested Chinook salmon from the coast of Washington in May 2003. The fish were divided into three groups of three fish each depending on the color of the flesh (Pearl, Marbled, or Red). The fish were delivered to the Oregon State University Seafood Laboratory in Astoria, Oregon for testing. The flesh for testing was collected from the upper loin (muscle) and belly flap section of each fish.

 

The percent total lipid content was found to be highly variable which is typical for wild-caught salmon. The belly flap had higher lipid content for all fish in each category. The lipid content of the three salmon was found to be generally lower than reported by other researchers. However, a direct comparison of the results was not possible as other studies usually reported results for the edible portion, which includes both the loin and the belly flap of the fish. All three salmon contained similar levels of fatty acids and all the salmon had low levels of omega-6 compared to omega-3. The ratio of omega-3/omega-6 was higher than reported by other researchers and considerable higher than found in farmed Atlantic salmon. The Pearl salmon had the highest lipid content for muscle and belly flap. Although marbled salmon had total lower lipid levels, the loin contained the highest DHA. The belly flap section of Pearl salmon contained the highest levels of omega-3 fatty acid. For all three salmon, the DHA content was higher in the loin than the belly flap while the EPA content was similar for both the loin and belly flap.

 

There were few differences in the fatty acids contents of the three flesh colors of Chinook salmon harvested in the ocean hook and line troll, hook and line caught, fisheries off the Washington coast. All three salmon colorations were found to have high percent levels of DHA and EPA and excellent omega -3/ omega -6 ratios.

 

Conclusion: The three flesh colored salmon were found to be excellent sources for omega-3 fatty acids for human consumption.