The polypeptide composition, structural properties and antioxidant capacity of gluten proteins of diverse bread and durum wheat varieties, and their relationship to the rheological performance of dough

Abstract

The aim of this study was to compare five bread and five durum wheat genotypes for gliadins and glutenins profiles, the concentration of free sulphhydryl groups and disulphide bonds, antioxidant capacity of gluten proteins and their bread-making performance. On average, bread wheat had significantly higher concentration of total sulphur-rich (S-rich) and sulphur-poor (S-poor) subunits of gliadins, as well as total low molecular weight (LMW) and high molecular weight (HMW) subunits of glutenins than durum wheat. However, durum wheat had higher concentration of S-rich gamma-gliadins and S-poor D-LMW-glutenins, but did not possess S-poor omega-gliadins. The concentration of disulphide bonds and total cysteine was higher in the durum gluten than that in the bread gluten, as well as antioxidant capacity (on average 90.6 vs. 85.9 mmol Trolox Eq kg(-1), respectively). In contrast to the bread wheat, the concentration of HMW-glutenins was negatively associated with extensibility, as well as resistance to extension in durum wheat flour dough.