On heating, aggregation and denaturation of the proteins occurs [22], which result in a decrease in
dough consistency (C2 value). Rice flour proteins expressed the lower weakening due to mechanical and
thermal constrains, while the amaranth flour were characterize with higher protein reduction and thus the
lower protein quality.
As heating proceeded, protein changes have minor influence and the starch granules have predominant
role in torque increase [11]. The increase in viscosity and thus in the torque is the result of the starch
granules swelling due to the water uptake and amylose chains leaching into the aqueous intergranular
phase [23]. Wheat flour contributed to a better starch performance of the samples (higher starch
gelatinization, C3) than wholegrain, pseudocereal and soybean flours. This could be ascribed to the
competence for water established between the starch and the bran present in the wholegrain and
pseudocereal flours [12]. The lower maximum peak, as well as the lower gelatinization rate (β), was
expressed by amaranth and soybean flour which had lower starch content and higher lipid content than
other raw materials (Table 1). The obtained results were in agreement with the finding that lipids form
complex with amylose that results in lowering peak viscosity [24]. On contrary, rice and corn flour, which
are rich in carbohydrates (Table 1), had higher maximum peak torques and gelatinization rates than other
flours.