Study on the mechanism of maize amylose addition to reduce viscosity of α, β, and γ-gliadin fractions

Abstract

Maize starch has often been used to reduce dough viscosity in China, but the mechanism about it is rarely reported in the literature. In this paper, maize amylose was mixed with α, β, and γ-gliadin fractions under different conditions to investigate its effects on the viscosity of α, β, and γ-gliadin fractions. The results showed that the addition of maize amylose in a ratio of 1:40 could reduce the viscosity of α, β, and γ-gliadin fractions from 9117.5 to 665.5 Pa s after stirring for 60 min at 40 °C. The results of microscopy and scanning electron microscopy showed that the interaction between maize amylose and α, β, and γ-gliadin fractions formed the backbone of gluten network structure at the expense of disulfide bonds in intermolecular β-sheet structures. The results of FTIR spectra suggested that the relatively weaker viscosity of maize amylose+α, β, and γ-gliadin fractions complex was because of its hydrogen bonds between two, which were formed with help of hydration of water. The hydrogen bonds bound to Gln Cδ (Qδ) of α, β, and γ-gliadin fractions were broken along with the formation of new ones between the fractions and maize amylose. The intensity of the diffraction peak of α, β, and γ-gliadin fractions at 2θ 27.42° (3.25 Å) increased at the expense of reduction at 2θ 30.46° (2.93 Å) and 57.02° (1.61 Å) after mixing with maize amylose. The findings of this paper provide a valuable basis for understanding the way of maize starch addition to reduce viscosity of dough.