Effect of Hydrocolloids on Water Absorption of Wheat Flour and Farinograph and Textural Characteristics of Dough

LINLAUD, N.E.; PUPPO, M.C.; FERRERO, C.

CEREAL CHEMISTRY

AACC International

Lugar: USA; Año: 2009 vol. 86 p. 376 - 382

0009-0352

The effect of  hydrocolloids addition on water absorption of flour and their influence on dough rheology were investigated. The influence of the selected hydrocolloids ((guar gum (GG), xanthan gum (XG), high methoxyl pectin (P), locust bean gum (LBG) and a 50:50 mixture of locust bean gum and xanthan gum (LBG+XG))  on water absorption was tested by different techniques: farinographic water absorption (A), water imbibing capacity (WIC), sodium dodecyl-sulfate sedimentation test (SDS ST) and sucrose solvent retention capacity (SRCs). The microstructural characteristics of dough were evaluated by scanning electron microscopy (SEM). The rheological behavior was analyzed through the farinographic parameters and texture profile analysis (TPA). Farinographic water absorption increased when increasing levels of gum were added, particularly in the case of XG addition.  WIC, SDS STand SRCs values markedly increased when XG or LBG + XG  were added. In farinographic assays, addition of NaCl increased dough stability in all cases respect to the mixture without salt.  Mixtures with GG exhibited the highest stability. TPA led to different behaviors according to water availability. When using farinographic water absorptions of mixtures, dough exhibited  decreased hardness and cohesiveness as hydrocolloid level was increased. At constant water (farinographic absorption of flour without gum), dough hardness increased when hydrocolloid proportion was higher.  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 and the type and concentration of hydrocolloid. SDS STand SRCs values markedly increased when XG or LBG + XG  were added. In farinographic assays, addition of NaCl increased dough stability in all cases respect to the mixture without salt.  Mixtures with GG exhibited the highest stability. TPA led to different behaviors according to water availability. When using farinographic water absorptions of mixtures, dough exhibited  decreased hardness and cohesiveness as hydrocolloid level was increased. At constant water (farinographic absorption of flour without gum), dough hardness increased when hydrocolloid proportion was higher.  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 and the type and concentration of hydrocolloid.