Effects of pentosanase and glucose oxidase on the composition, rheology and microstructure of whole wheat dough

Abstract

In the present study, the effects of pentosanase (Pn) and glucose oxidase (GOX) on the properties of whole wheat steamed buns dough were investigated, including the composition, rheology, and microstructure, to reveal the effects and mechanisms of action of these two enzymes in whole wheat steamed buns making. Compared with the Control, the dough exhibited a higher content of water extractable arabinoxylan and a stronger solubility in protein in the presence of Pn. Additionally, Pn-treated dough showed high extensibility, with the gluten matrix more open and the starch granules more visible. On the other hand, the addition of GOX decreased the number of free sulfhydryls and increased the content of glutenin macropolymer (GMP), indicating the formation of disulfide bonds. Reducing SDS-PAGE of albumin and globulin suggested the generation of large protein aggregates and the conjugation of protein-polysaccharide by non-disulfide covalent bonds. The GOX-treated dough was significantly strengthened, which generated a more continuous and highly dense gluten network. Although the effects of Pn and GOX on the dough were considerably different, they both significantly changed the rheology and microstructure of the dough, due to the solubilization of water un-extractable arabinoxylan and the increase of GMP and the formation of protein-polysaccharide conjugates. These effects observed for steamed buns could be extended to other fermented flour products.