Lipidomics of common octopus' (Octopus vulgaris) arm muscle using untargeted high-resolution liquid chromatography-mass spectrometry

The common octopus, Octopus vulgaris, is one of the most important cephalopod fisheries in the world. In Mediterranean cuisine, the common octopus is perceived as an ingredient highly valued for its palatability and nutritional value (source of omega 3 fatty acids). However, the polar lipids of this species are still poorly un-derstood. The present study performed the first fingerprinting of the polar lipidome of the arm muscle of O. vulgaris using a high-resolution mass spectrometry HILIC-LC-MS lipidomics approach. Samples of common octopus were sourced from specimens landed in Santa Luzia (Tavira, Algarve, Portugal), the most important octopus mono-specific fishing harbour in mainland Portugal. Nearly 400 lipid species have been identified from 13 classes of polar lipids. Phosphatidylcholine and phosphatidylethanolamine were the main phospholipids recorded, while the phosphonolipid CAEP and ceramides were the main sphingolipids identified. The structural characterization recognised a high proportion of essential fatty acids, such as EPA, DHA and several other very -long-chain fatty acids (24:5, 24:6) esterified in the polar lipids. The present study provides an unprecedented elucidation of the polar lipidome of O. vulgaris that can be used as a reference for future studies on nutritional value, ecology and traceability of geographic origin.