Rheological properties and microstructure of xylanase containing whole wheat bread dough.

The present research work was undertaken to investigate the effect of xylanase, produced by Penicillium citrinum, on rheological behavior of whole wheat bread dough at large and small deformation respectively. Dough attributes including textural properties (penetration) and structure related characteristics (oscillatory tests) were evaluated. Change in visco-elastic properties of xylanase containing dough was evaluated by oscillatory and creep measurements. The flow experiments were conducted under steady-state condition with shear rate ranging from 0.01 to 100 s-1. Frequency sweep experiments were performed between 0.01 and 10 Hz. It revealed that in both control and xylanase containing dough formulation, the elastic modulus was higher than viscous modulus in the entire range of frequency. Our results represent the adequacy of fitting of dynamic moduli in Power law model and week gel model. Peleg model as well as six element Kelvin model described well the creep behaviour of control and xylanase-containing dough. Uniaxial extensibility was assessed by Kieffer dough and gluten extensibility rig. Lyophilized powder of untreated and xylanase treated doughs were tested under scanning electron microscope. FTIR spectra of lyophilized powder of untreated and xylanase treated dough were recorded in the range of 600-4000 cm-1.