The overexpression of high-molecular-weight glutenin subunit Bx7 improves the dough rheological properties by altering secondary and micro-structures of wheat gluten. (April 2020)

• Record Type: Journal Article
• Authors: Li, Shaopeng; Liu, Yingchun; Tong, Jingyang; Yu, Liwei; Ding, Mengyun; Zhang, Zhengmao; Rehman, Ata-ur; Majzoobi, Mahsa; Wang, Zhonghua; Gao, Xin
• Is Part Of: Food research international. Volume 130(2020)
• Publication Date: 2020-04
• Subjects: Bx7 glutenin subunit expression levels -- Wheat gluten -- Secondary structures of gluten -- Quantitative analysis of gluten structure during dough mixing -- Wheat dough rheology; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2019.108914
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: This study clarified the effects of Bx7 subunit expression levels on wheat gluten. Micro-structures of gluten at three stages during dough mixing were analysed. Bx7 OE subunit speeds up the accumulation of glutenin polymers during grain filling. Bx7 OE increases the contents of β-sheets and intermolecular β-sheets in wheat gluten. Bx7 OE gives larger protein area, and makes the micro-structure of gluten much denser. Abstract: Bread wheat ( Triticum aestivum L.) is one of the crucial cereals consumed by human beings and wheat gluten, the natural macromolecules, mainly determines the processing quality of wheat dough. The high-molecular-weight glutenin subunits (HMW-GSs) of gluten proteins are recognized as one of the main components regulating the rheological properties of dough. The overexpressed Bx7 subunit (Bx7 OE ) has been reported to improve wheat quality and rheological properties of dough, however its effect on secondary and micro- structures of gluten is still unclear. In this study, we evaluated the composition of main storage proteins in wheat grains of two near-isogenic lines and studied the effect of Bx7 subunit expression level on the secondary structures of gluten and micro-structure of gluten during dough mixing process. Results showed the protein content, HMW-GSs proportion in total glutenins and free sulfhydryl content increased in the flour of HMW-Bx7 OE wheat line, and the accumulation of unextractable polymeric protein during grain filling stage accelerated. It was found that the content of β-sheets in secondary structures of gluten increased and a more compact micro-structure of gluten network formed in the dough. Protein network analysis characterized and quantified the alterations in the gluten micro-structure. In the process of dough mixing, protein area, total protein length, number of junctions and branching rate reach the peak at dough development time, which was consistent with Chopin mixing profile. Interestingly, during dough mixing, the above-mentioned parameters of HMW-Bx7 OE showed less changes than those of HMW-Bx7 wheat line, indicating Bx7 OE improved the dough stability during mixing. To conclude, Bx7 OE alters the secondary and micro- structures of gluten and thus improves the mixing and rheological properties of wheat dough.