Interactions between dietary fiber and ferulic acid change the aggregation of glutenin, gliadin and glutenin macropolymer in wheat flour system

Background Glutenin macropolymer (GMP), glutenin and gliadin proteins are important indicators of the baking quality of dough. This study investigated the impacts of wheat bran and a mixture of ferulic acid (FA) and dietary fiber (DF) on the constitution of gluten proteins. Addition of wheat bran (100 and 150 g kg-1 ) into gluten decreased the gliadin/glutenin ratio, while the addition of different amounts of FA + DF (C1 group: 20 g kg-1 FA and 60 g kg-1 DF; C2 group: 30 g kg-1 FA and 90 g kg-1 DF) had the opposite effect. Results The GMP contents of wheat bran groups (B1 group: 100 g kg-1 ; B2 group: 150 g kg-1 ) were similar to that of the control group, and disulfide bond contents were increased. However, both GMP and disulfide bond contents of FA + DF groups significantly decreased. The GMP gel properties and microstructures were destroyed after addition of wheat bran and FA + DF. The wheat bran and FA + DF additives induced different effects on the thermal properties and secondary structures of glutenin, gliadin and GMP. Conclusions The results suggest that the interaction mechanism of bran fractions and gluten proteins is not only related to the physicochemical properties of the additives, but also to interactions between the additives and the components of gluten protein. © 2020 Society of Chemical Industry.