Evaluation of triacylglycerol (TAG) profiles and their contents in salmon muscle tissue using ESI-MS/MS spectrometry with multiple neutral loss scans.

Identification and quantification of triacylglycerols (TAGs) in salmon muscle tissue were conducted using electrospray ionization (ESI)-MS/MS in a triple quadrupole mass spectrometer. The confirmation of three fatty acid moieties of individual TAGs was determined using the multiple neutral loss (NL) scanning mode. A total of 98 TAGs were identified, and the predominant TAG species were 16:0-18:0-20:5 (10.4%), 18:1-18:2-22:6 (9.0%), and 18:0-18:1-22:6 (16.4%) in salmon muscle tissue. NL scanning was an effective means to confirm the three fatty acid moieties of the TAGs, leading to the rapid and accurate identification of individual TAGs. To the best of our knowledge, this is the first application of multiple neutral loss scanning to identify TAGs in salmonoid tissue, and many TAG species have been newly identified (i.e., 18:1-18:2-22:6, 16:0-18:2-20:5, 18:1-18:2-20:5, etc.). This study showed that the shotgun lipidomic approach along with NL scans is a useful means for studying TAG metabolism in fish.