Consecutive extraction of neutral and polar lipids from skipjack tuna (Katsuwonus pelamis) byproducts using supercritical carbon dioxide

This study aimed at the consecutive extraction of neutral and polar lipids (phospholipids) from skipjack tuna (Katsuwonus pelamis) byproducts using an entrainer (ethanol) combination of green extraction system supercritical carbon dioxide. The head, viscera, and skin of tuna fish were subjected to extraction. The highest proportion of lipids was obtained from the skin (31.18% +/- 0.59%), and the net phospholipids were obtained from the head (3.24%). Oils and phospholipids are rich in omega -3 and omega -6 polyunsaturated fatty acids. Phospholipids were identified and their composition was analyzed based on 31P NMR spectra. Three important classes of phospholipids are phosphatidylcholines (PC), phosphatidylethanolamine (PE), and lysophosphatidylcholine (LPC). Tocopherol is the major vitamin present in oils and phospholipids from K. pelamis byproducts. Thermogravimetric analysis and differential thermogravimetric analysis confirmed that the extracted neutral and polar lipids are stable at cooking temperatures and can be used in various industries.