Use of the 1H NMR technique to describe the kneading step of wholewheat dough: The effect of kneading time and total water content

Abstract

The kneading step of wholewheat flour (WWF) dough was monitored using low-resolution ¹H nuclear magnetic resonance (NMR). The tested variables were kneading time and total water content. Two ¹H Free induction decay (FID) (A and B) and four ¹H T₂ Car-Purcell-Meiboom-Gill (CPMG) (C, D, E and F) proton populations were observed and the attribution to the different proton domains was made based on the literature and data acquisition. Kneading time significantly increased the mobility and the relative abundance of popA, the relative abundance and strength of protons of popC, D and E, while significantly reducing the relative amount of popF and increasing its mobility. This evolution of the proton populations during kneading was interpreted as chemical/physical transformations of the flour constituents. The use of WWF may reveal the changes in molecular dynamics underlying the higher water requirements of unrefined doughs, often associated with improved bread quality.

Keywords: Mixing step; Molecular mobility; Unrefined flour; Wheat dough.