Reversible and irreversible changes in protein secondary structure in the heat- and shear-induced texturization of native pea protein isolate

Nakagawa, Hiroshi   ; Ubbink, J.*

The molecular mechanism of plant protein texturization under extrusion conditions was unraveled at the secondary structure level by decoupling the effects of heating, cooling and shearing on protein secondary structure. Upon heating without shearing, native alpha-helices and intramolecular-beta-sheets unfold to random domains, followed by the formation of intermolecular beta-sheets, inducing aggregation. During cooling, the intermolecular beta-sheets become increasingly ordered, and random domains partially fold into non-native beta-structures. Combined heating and shearing results in more extensive beta-sheets than heating alone. The resulting beta-rich structures provide for an entangled network of protein chains and a cohesive protein matrix.