Comprehensive metabolomic and lipidomic profiling of the seasonal variation of blue mussels (Mytilus edulis L.): Free amino acids, 5′-nucleotides, and lipids

Blue mussel (Mytilus edulis L.) is a shellfish with high nutritional and economic value. Free amino acids (FAAs), 5'-nucleotides, and lipids that affected the nutritional value and flavor of blue mussels varying with the seasons were analyzed using stable isotope labeling-liquid chromatography coupled with tandem mass spectrometry (SIL-LC-MS/MS) and ultra-performance liquid chromatography-Q-Exactive orbitrap tandem mass spectrometry (UPLC-Q-Exactive Orbitrap-MS). FAAs and 5'-nucleotides were most in the summer. Changes in FAAs between seasons were more obvious than those between genders, except in spring, when females were in the reproductive period. A total of 413 lipids were annotated in blue mussels for one year. Seasonal variation in triacylglycerols (TAGs) was the most evident. TAGs were dominant in females, while phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) were dominant in males. Overall, blue mussels in summer were more delicious and nutritious. Thus, such findings are of great significance to the seasonal preference of deep processing and consumption of mussel products.