Impacts of konjac glucomannan on the physicochemical and compositional properties of gluten with different strengths

Konjac glucomannan (KGM) is a kind of non-ionic hydrocolloid dietary fiber widely used in the food and pharmaceutical industries. In this study, we aimed to understand the impacts of KGM on dough textural properties, gluten molecular chain morphology, covalent and non-covalent interactions, gluten molecular weight, and different subunits distributions of weak, middle, and strong gluten samples. After treatment with 0.1 g g⁻¹ KGM, disulfide and hydrogen bonds were destroyed in middle and strong gluten, which resulted in the fracture of the crosslink between glutenin and gliadin subunits (α-gliadin and γ-gliadin) and in turn caused a severe decline in gluten molecular chain height. Besides, the breaking of hydrogen bonds caused by 0.1 g g⁻¹ KGM in middle gluten was an adverse factor for gluten aggregation. These changes led to a decrease in dough hardness for middle and strong gluten. Although the disulfide bonds were destroyed in weak gluten when 0.1 g g⁻¹ KGM was treated, it formed more hydrogen bonds and then increased the gluten molecular chain height and improved gluten aggregation. These findings could serve as a foundation for creating more inventive KGM-based foods.