Characterization of phenolic compounds extracted from wheat protein fractions using high-performance liquid chromatography/liquid chromatography mass spectrometry in relation to anti-allergenic, anti-oxidant, anti-hypertension, and anti-diabetic properties

The purpose of this study was to identify novel natural bioactive phenolic compounds with anti-oxidant, anti-allergic, anti-hypertensive, and anti-diabetic properties in wheat protein fractions. Free and bound phenolic compounds were isolated from the albumin, glutelin-1, glutelin-2, prolamin, and globulin wheat protein fractions. The biological properties of the extracted phenolics were analyzed in vitro using 1,1-diphenyl-2-picryl-hydrazyl assays, enzyme-linked immunosorbent assays, angiotensin-1 converting enzyme assays, and -amylase assays. The free and bound phenolic compounds were identified using liquid chromatography electrospray ionization tandem mass spectrometry methods. The aromatic rings in globulin were the highest in both before and after the removal of phenolic compounds (1.13 and 1.05 mg/g). The highest values of angiotensin-1 converting enzyme inhibitory and -amylase inhibition (%) were obtained in glutelin-1 (73.17 and 96.41%, respectively) before removal phenolic compounds. The biological activity was affected by the presence or absence of phenolic compounds. Allergenicity was minimized in the presence of phenolic compounds. Correlation coefficients between wheat protein fractions and biological properties are described.