Relationship of molecular weight distribution profile of unreduced gluten protein extracts with quality characteristics of bread

Abstract

A statistical correlation was established among the molecular weight distribution patterns of unreduced gluten proteins and physicochemical, rheological and bread-making quality characteristics of wheat varieties. Size exclusion chromatography fractionated the gluten proteins apparently into five peaks. Peak I signified glutenins (30–130kDa), peak II as gliadins (20–55kDa), peak III as very low molecular weight monomeric gliadins (10–28kDa), peak IV and V, collectively, as albumins and globulins (<10kDa). Peaks I and II had appreciable effects on dough development time (r=0.830∗∗ and r=−0.930∗∗) and dough stability (r=0.901∗∗ and r=−0.979∗∗). Peak I was associated with R/E ratio (r=0.745∗∗), gluten index (r=0.959∗∗), and gliadin/glutenin ratio (r=−0.952∗∗), while peak II influenced inversely as expected. Peak I exhibited positive statistical significance with bread loaf volume (r=0.848∗∗); however, peak II had negative (r=−0.818∗∗) impact. Bread firmness increased with increment in peak II (r=0.625∗∗), and decreased with accretion in peak I (r=−0.623∗∗).