Differentiation of Whole Grain from Refined Wheat (T. aestivum) Flour Using Lipid Profile of Wheat Bran, Germ, and Endosperm with UHPLC-HRAM Mass Spectrometry

A comprehensive analysis of wheat lipids from milling fractions of bran, germ, and endosperm was performed using ultrahigh-performance liquid chromatography-high-resolution accurate-mass multistage mass spectrometry (UHPLC-HRAM-MS(n)) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) in both positive and negative modes. About 155 lipid compounds, including free fatty acids (FA), oxylipins, alk(en)ylresorcinols (ARs), γ-oryzanol, sphingolipids, triglycerides (TGs), diglycerides (DGs), phospholipids, and galactolipids were characterized from the three milling fractions. Galactolipids and phospholipids were proposed to be potential discriminatory compounds for refined flour, whereas γ-oryzanols, ARs, TGs, and DGs could distinguish whole wheat flour from a refined one based on principal component analysis (PCA).