Pre-harvest Modulation of N-3 Long-chain Polyunsaturated Fatty Acids in Rainbow Trout Meat for Human Consumption

Since post-harvest improvement of food quality depends on the pre-harvest stage, controlling food quality at the pre-harvest stage is being recognized as an important aspect of food processing technology. n-3 Long-chain polyunsaturated fatty acids (n-3 LCPUFAs) are considered important factors in the suppression of cardiovascular disease and development of the infant brain and visual functions. Fish meat generally contains a larger amount of n-3 LCPUFAs than meat from terrestrial animals, but the amount of n-3 LCPUFAs in fish meat depends on their dietary fatty acid intake. In order to supply n-3 LCPUFAs to consumers, we developed a finishing-up method, through a 4-day lysine-deficient diet feeding for rainbow trout (Oncorhynchus mykiss) meat. This 4-day lysine deficiency did not affect fish body weight, while significantly increased the total lipid content in the muscle tissue. In addition, docosahexaenoic acid and total n-3 fatty acid contents increased significantly in the meat throughout the 4-day finishing treatment. We concluded that the finishing-up method using short-term lysine-deficient diet feeding enables us to enrich fish meat with n-3 fatty acids for human consumption.