Effect of hydrocolloids on water absorption of wheat flour and farinograph and textural characteristics of dough

Abstract

The effect of hydrocolloids addition (0-25-1.5 g/100g flour) on water absorption of flour and their influence on dough rheology were analyzed. The influence of guar gum (GG), xanthan gum (XG), high methoxyl pectin (P), locust bean gum (LBG) and a 1:1 mixture of locust bean gum and xanthan gum (LBG+XG) on water absorption was tested by different techniques: farinograph water absorption (A), water imbibing capacity (WIC), sodium dodecyl-sulfate sedimentation test (SDS ST) and sucrose solvent retention capacity (SRCs). The rheological behavior was analyzed through the farinograph parameters and texture profile analysis (TPA). Principal Component Analysis (PCA) was applied to evaluate the behavior of the different mixtures. Absorption values obtained by different methods were increased by XG and LBG+XG addition, particularly at the highest levels (1-1.5%). Flour-pectin mixtures showed the lowest absorption. Guar gum added mixtures led to the more stable doughs and pectin to the less stable ones. Addition of NaCl increased stability in all cases. According to TPA, softer and less cohesive doughs than control were obtained when hydrocolloids were added, both in conditions of water availability and water restriction (except for xanthan gum and guar gum at the highest levels). However, when enough water was added, more variation on textural attributes among doughs could be observed by PCA. No remarkable differences respect to control were observed in gluten network, as evaluated by SEM. Hydrocolloids incorporation led to rheological changes in dough; the trend and degree of this effect was affected by the amount of water added, the structure and concentration of hydrocolloid.