Effect of soluble oat β-glucan and tea polyphenols on the rheological properties and microstructure of wheat dough

Considering the prevalent coexistence of dietary fiber and polyphenols in wheat flour-based products, the effects of oat β-glucan (OβG), tea polyphenols (TP), and the combination of the two (OβG + TP) on the rheological properties and microstructure of dough were investigated. The increasing concentration of OβG (from 1 g/100g to 5 g/100g) decreased the water absorption of dough by 11.8%, whereas increased the resistance to extension by 26.7%. However, the addition of TP (from 0.5 g/100 g–2 g/100g) induced a reverse trend. In the “OβG + TP” system, OβG exerted a more remarkable influence on water absorption and pasting properties than TP due to its viscosity and gel-forming properties. However, TP had a more profound impact on degree of softening, stability, and extensibility of dough, which may be due to its strong reducibility and preferential reaction with gluten protein. At a low concentration (≤OβG + TP-(3 + 1)), TP had a predominant influence on viscoelasticity, whereas at a high concentration (OβG + TP-(5 + 2)), OβG showed a predominant impact. Besides, the destruction of gluten structure and starch exposure were more remarkable with the increasing concentration of OβG + TP.