Rheological Behaviour of Formulated Bread Doughs During Mixing and Heating

Abstract

During breadmaking different physicochemical phenomena occur producing discernible changes in the rheological properties. Traditionally, these changes have been studied with equipments controlling separately the mixing step and the baking process. The MIXOLAB is a new apparatus which measures torque when bread dough is subjected to a dual mixing and temperature constraint. It was the aim of this study to compare this new tool with other available methodologies in order to explore its use as a suitable technique for determining bread dough rheological properties. A broad range of correlations was found, not only within parameters derived from the MIXOLAB, but also with standard methods as the pasting method performed by the Rapid Visco Analyser, the gluten index and uni- and bi-axial extensional measurements. The use of MIXOLAB has also allowed the identification of the influence of design factors (flour and exogenous enzymes) on the rheological properties. These results confirm MIXOLAB as a promising tool for the rheological assessment of bread dough.

Estimation of the baking quality of wheat flours based on rheological parameters of the mixolab curve

“…The changes of the Mixolab curve trend depended on the value of the falling number and were correlated with the results of the baking tests. In agreement with the obser vations by Kahraman et al (2008) and Collar et al (2007) we may conclude that Mixolab is a promising tool for the rheological assessment of the bread dough. Vt -total volume of CO 2 Vr -volume of the gas retained in the dough at the end of the procedure Cr -retention coefficient H'm -maximum dough fermentation height t1 -the time at which dough attains the maximum height tx -the time when gas starts to escape from the dough…”

“…Moreover, Collar et al (2007) compared the Mixolab test with other methodologies available (pasting method performed by the Rapid Visco Analyser, the gluten index, and uni-and bi-axial extensional measurements) in order to explore its use as a suitable technique for determining the bread dough rheological properties.…”

“…The nonlinear viscoelastic behaviour of wheat flour dough is mainly due to the continuous gluten matrix and starch granules embedded in it ( Edwards et al 2002;Tronsmo et al 2003;Agyare et al 2004;Collar et al 2007). It has typical properties of both solid and liquid bodies, and an intermediary rheological behaviour between the ideal solid and fluid bodies.…”

“…Different empirical methods based on classical Extensograph, Alveograph, Farinograph, and Mixograph instruments are currently employed to obtain accurate data on the baking properties of the respective flour, by simulating the bread making steps (Autio et al 2001;Chung et al 2001;Chiotelli et al 2004;Collar et al 2007).…”

Effects of Germination and Fermentation on the Functionality of Whole Soy Flour

“…Different water volumes were added to the doughs such as to get a constant C1 torque of about 1.1 Nm at 30 o C. The following typical parameters of the Mixolab curve were registered: C2 (Nm) gives indication about protein weakening when subjecting the dough to double constraints of mechanical work and temperature; C3, C4 and C5 (Nm) are related to starch behavior and give indications on gelatinization, stability of the gel and retrogradation during the cooling stage, respectively (Collar et al, 2007).…”