Plasmalogens are an animal-derived functional phospholipid increasingly known as a safe and effective nutritional ingredient, however, the quantitation and comparison of plasmalogen species in foods is limited. In the present work, determination methods for dietary plasmalogens using liquid chromatography-tandem mass spectroscopy under positive and negative ionization modes were compared. The negative-mode method, which showed better selectivity, sensitivity, and accuracy, was then applied in 14 kinds of livestock, poultry, and seafood samples. Livestock and poultry showed abundant total plasmalogen (530.83-944.94 nmol/g), higher than fish (46.08-399.75 nmol/g) and mollusk (10.00-384.76 nmol/g). While fish and mollusk samples expressed healthier fatty acyl composition, with higher eicosapentaenoyl and more beneficial n-6/n-3 ratio than the land animal meats, especially for squid and octopus, with eicosapentaenoyl of 98.4% and 94.5%, respectively. The correlations among plasmalogen species varied in different foodstuffs with distinguishing patterns, suggesting the customizable strategies for achieving targeted plasmalogen species. These findings not only provided fundamental comparison of plasmalogen among daily foodstuffs, but also contributed to extend the dietary plasmalogen sources for health food development.
Keywords: LC-MS/MS; choline plasmalogen; ethanolamine plasmalogen; fatty acyls; livestock and poultry; molecular species; seafood.