Chemical characterization of Trachinotus ovatus oil for its potential application as human milk fat substitute

Abstract

Trachinotus ovatus (TO) is an important cultured marine fish, which is popular with customers for its high muscle quality and favorable price. In this study, lipids in viscera, bone and muscle of TO were extracted and analyzed to identify unique applications. Total lipid content based on dry mass was 34.50% in muscle, 46.25% in bone, and 64.35% in viscera. In the lipid composition of TO oil (TOO), the contents of free fatty acids, diglycerides and phospholipids ranged from 3.54% to 7.21%, 1.88%–4.66% and 4.91%–6.35%, respectively. Phospholipids were mainly composed of phosphatidylcholine and phosphatidylethanolamine. Triglycerides were the major component in TOO for all tissues, the content range was 83.16%–89.39%. The main fatty acids of triglyceride fraction in TOO were palmitic acid (~24%), oleic acid (~26%), and linoleic acid (~26%). It is interesting to observe that palmitic acid was preferentially distributed at the sn-2 position. Ultra-high performance combined-phase chromatography combined with quadrupole time-of-flight mass spectrometry analysis showed that 1-oleoyl-2-palmitoyl-3-linoleoylglycerol was the highest content of triglyceride molecule in TOO, accounting for about 17%, followed by 1,3-dioleoyl-2-palmitoylglycerol. These unique composition and positional distribution in TOO are very similar to those of human milk fat. Therefore, TOO has a great potential in the preparation of human milk fat substitutes.