Distribution of Lipids in the Grain of Wheat (cv. Hereward) Determined by Lipidomic Analysis of Milling and Pearling Fractions

Lipidomic analyses of milling and
pearling fractions from wheat
grain were carried out to determine differences in composition that
could relate to the spatial distribution of lipids in the grain. Free
fatty acids and triacylglycerols were major components in all fractions,
but the relative contents of polar lipids varied, particularly those
of lysophosphatidylcholine and digalactosyldiglyceride, which were
enriched in flour fractions. By contrast, minor phospholipids were
enriched in bran and offal fractions. The most abundant fatty acids
in the analyzed acyl lipids were C16:0 and C18:2 and their combinations,
including C36:4 and C34:2. Phospholipids and galactolipids have been
reported to have beneficial properties for breadmaking, whereas free
fatty acids and triacylglycerols are considered detrimental. The subtle
differences in the compositions of fractions determined in the present
study could therefore underpin the production of flour fractions with
optimized compositions for different end uses.