Impact of reducing and oxidising agents on the wheat flour dough dynamic rheological properties

Abstract

Dynamic measurements with an oscillatory rheometer were made to study the rheological properties of wheat flour doughs and to examine how they are related to the composition of dough (the addition of oxidising and reducing agents). It was found that L-cysteine hydrochloride monohydrate (0.6 × 10 -2 - 4.0 × 10-2 wt.%), L-cysteine p. a. (0.6 × 10-2 - 1.4 × 10-2 wt.%) and glutathione-inactivated dry yeast (1.8 × 10-2- 14.0 × 10-2 wt.%) show softening effects. An interesting phenomenon was observed from the concentration of 2.4 × 10-2 wt.% of L-cysteine p. a., where proces of weakening was decelerated. L-cysteine start making cystine by reaction of two cysteine molecules and proces of weakening was decelerated. L-threonine, L-tryptophan within the concentration range of 2.0 × 10-2 - 14.0 × 10-2 wt.% and L-tyrosine, especially at concentrations 10.0 × 10-2 - 14.0 × 10-2 wt.%, have strengthening effects. L-cysteine hydrochloride monohydrate exhibited the strongest softening effect while L-tryptophan had the strongest stiffening effect on the gluten network.