Composition and distribution of individual molecular species of major glycolipids in wheat flour

The distribution of individual molecular species of the main wheat flour glycolipids, digalactosyldiglyceride (DGDG), monogalactosyldiglyceride (MGDG), digalactosylmonoglyceride (DGMG) and monogalactosylmonoglyceride (MGMG) has been investigated by reversed phase high-performance liquid chromatography of their benzoate derivatives after the respective galactosylglyceride classes were obtained by semi-preparative high-performance liquid chromatography. Combinations of linoleic acid at thesn-2 position with linoleic, oleic and palmitic acids at thesn-1 position predominated as major common molecular species of MGDG and DGDG. The pairs 16:0/20:4, 18:3/20:1, 18:0/18:3, 18:0/18:1 and 20:0/18:2 were determined only among MGDG molecular species. Five common molecular species containing 16:0, 18:0, 18:1, 18:2 and 18:3 fatty acids, respectively, were determined in MGMG and DGMG, with 18:2 being the most predominant form, and 18:1 (MGMG) and 16:0 (DGMG) as the next major fatty acids.