Glycerophospholipid and triacylglycerol distribution in corn kernels (Zea mays L.)

The distribution of various molecular species of triacylglycerols (TAGs) and phospholipids among three corn kernel parts was determined by LC/ESI-MS. A comparison between three corn kernel parts demonstrated that there was a significant (p < 0.05) difference in their contents of various glycerophospholipid classes. Phosphatidylcholine was the most abundant class in germ and pericarp fractions (51.4–70.6% of the total glycerophospholipids), followed by phosphatidylinositol (11.3–25.1%) and phosphatidylethanolamine (8.4–12.6%). In contrast, phosphatidylethanolamine was found to be the most abundant class in the endosperm fraction (41.4–48.5%), followed by phosphatidylcholine (30.2–33.4%) and phosphatidylinositol (13.2–14.4%). Various molecular species were detected in each class of glycerophospholipid and their levels were significantly (p < 0.05) different among three corn kernel fractions. The major molecular species of triacylglycerol detected in three corn parts were OLL, OOL, LLL, POL, PLL, OOO and POO; where L represents linoleic acid; O, oleic acid; and P, palmitic acid. The TAG composition was significantly different among three corn kernel fractions. In Astro germ fraction, LLL (27.2%) was detected as the dominant TAG molecular species, followed by OLL (21.9%) and PLL (13.4%); however in Astro endosperm fraction, OLL (21.5%) was the major form followed by PLL (18.6%) and LLL (13.5%).