Relationship between rheological properties and microstructural characteristics of nondeveloped, partially developed, and developed doughs

Farinography and mixography are two commonly used procedures for evaluating dough properties. These procedures, however, cannot separate hydration and energy input during dough development, both of which are critically import ant for understanding fundamental rheological properties of dough. A rheome ter and laser scanning confocal microscopy (LSCM) were used to study the re lationship between rheological properties and microstructural characteristi cs of developed (by farinograph with both shear and extensional deformation s), of partially developed (by rheometer with either shear or extensional d eformation), and of nondeveloped (no deformation) dough samples of wheat fl ours. Rheological data revealed that developed dough had the highest G* (mo st elastic or strong), followed by doughs partially developed with extensio nal deformation, and then shear deformation, and finally by nondeveloped do ugh. The LSCM z-sectioning (scanning of different layers of the sample) and the analysis of amount of protein matrix showed that developed dough had t he most protein matrix and nondeveloped dough had the least protein matrix. It also showed that the higher the G*, the greater the protein network. Mo reover, the type of deformation appeared to contribute to the development o f protein matrix and further increase the dough strength. In this study, a combination of shear and extensional deformations by farinograph produced t he most protein matrix and the strongest dough, followed by extensional def ormation, shear deformation, and then no deformation.