Formation of macromolecules in wheat gluten/starch mixtures during twin‐screw extrusion: effect of different additives

Abstract

The findings of the present study demonstrate that extrusion might affect the texture and quality of extruded wheat gluten-based foods and suggest that this process might serve as a basis for the high-value application of wheat gluten products. © 2017 Society of Chemical Industry.

Physical modifications of wheat gluten protein: An extensive review

“…Fluorescence emission spectra provide information concerning fluorescent amino acids, including tryptophan and tyrosine residues. The fluorescence emission maximum ( λ max ) of native wheat gluten is around 335 nm, which is consistent with the characteristic fluorescence profile of tryptophan residues in approximately hydrophobic environment (Wang et al, 2017). A red shift in λ max with the reduction in the intensity of the fluorescence emission peak to 257 and 150 nm was reported in the samples treated at 40 and 50°C, respectively, which is attributed to the protein structure unfolding, the exposure of buried tryptophan residues and the subsequent aggregation, polymerization, or peptide–peptide association.…”

“…Dynamic rheological characteristics, such as the loss ( G ″, viscous behavior) moduli and storage ( G ′, elastic behavior) are closely associated with water holding capacity, swelling properties, and molecular weight and size (Banc, Dahesh, Wolf, Morel, & Ramos, 2017; Savadkoohi & Farahnaky, 2012; Wang et al, 2017). The wheat gluten dispersion shows a reduction in G ′ with the increase in temperature (from 25 to 60°C), which is consistent with the protein denaturation process and reduction of physical interactions (hydrogen and ionic bonds).…”

“…A red shift in λ max with the reduction in the intensity of the fluorescence emission peak to 257 and 150 nm was reported in the samples treated at 40 and 50°C, respectively, which is attributed to the protein structure unfolding, the exposure of buried tryptophan residues and the subsequent aggregation, polymerization, or peptide–peptide association. In other words, protein polymerization is prone to dityrosine formation (Wang et al, 2017; Wang, Zou, Gu, et al, 2018).…”

“…The fluorescence peak intensity once increased to 354.5 nm with the increase in the gelling temperature from 60 to 90°C. A blue shift in λ max (Wang et al, 2017) is accompanied by disappearation the random coil structure, and the amount of intermolecular β‐sheets increased upon protein aggregation (Georget & Belton, 2006; Wang et al, 2017).…”

“…The reaction of glutenin with gliadin molecules follows a first‐order rate law (Delcour et al, 2012; Jansens et al, 2011; Lambrecht, Rombouts, De Ketelaere, & Delcour, 2017; Rombouts et al, 2013; Wang et al, 2017; Wang et al, 2015; Wang, Zou, Gu, et al, 2018). Heating up to a minimum of 90°C results in SS‐linked aggregates between mainly glutenin and α‐ and γ‐gliadins.…”