Physicochemical properties of protein from pearling fractions of wheat kernels

Abstract

AbstractBackgrounds and objectivesThe protein from various parts of the wheat kernel has different physicochemical properties, which is one of the reasons for the different processing characteristics of the corresponding flour made from these parts. In this study, wheat kernels were pearled into seven fractions from the outermost to the innermost layers to evaluate the quantitative and conformational properties of protein fractions from different pearling fractions.FindingsThe crude protein and protein fraction content was lower in the corresponding pearling fractions that were closer to the center of the endosperm. The albumin and SDS‐soluble protein contents in the total protein from the pearling fractions exhibited a similar trend, whereas the dry gluten content exhibited an opposite trend. The average molar mass (Mw), polydispersity index (Mw/Mn), and density (ρ) of the SDS‐soluble protein were decreased, but there was no significant difference in the Rgz. And the G′ plateau values of glutenin macropolymer (GMP) were increased.ConclusionsProtein conformation of the inner endosperm was looser than the other pearling fractions. Loose network wrapped more protein that led to the increased proportion of dry gluten. And it may increase aggregate entanglement that attributed to GMP became more elastic.Significance and noveltyThe changes in protein conformation in pearling fractions of wheat kernels further explained changes in physicochemical properties of protein from different pearling fractions.