The further reduction in viscosity (C4 value) is the result of the physical breakdown of the granules
due to the mechanical shear stress and the temperature constraint [11]. Breakdown torque (C3-C4) is also
a measure of amylase activity. Namely, the greater the difference between C3 and C4 is, the greater the
amylase activity is. Subsequently, on cooling, starch retrogrades and the consistency increases (C5 value)
[12]. According to the results summarized in Table 2, flours obtained from pseudocereals (buckwheat and
amaranth) exhibited the lowest breakdown torques and cooking stability rates. Namely, Ikeda et al. [25]
proved that buckwheat seed contains an α-amylase inhibitor which resulted in lower C3-C4 values. Since
cooking stabilities could be related with extended shelf life of bread [12], it can be concluded that breads
containing pseudoceral flours would express slower increase in bread firming during storage. Moreover,
amaranth flour had the lowest final (C5) and setback torque (C5-C4), and thus the lowest starch
retrogradation.
4. Conclusion
Flours from different raw materials were tested in order to investigate their ability to mimic wheat
flour dough behaviour during bread making and bread baking. Among tested alternative cereals (rice,
corn), pseudocereals (buckwheat, amaranth) and legumes (soybean), rice and buckwheat flours expressed
the most similar protein (water absorptions, stabilities and degrees of mechanical weakening) and starch
(peak, minimum and setback torque) characteristics as wheat flour. Since Mixolab profile of wheat flour
was located between rice and buckwheat flour profiles, it can be concluded that blends of rice and
buckwheat flours would give the optimal rheological profile.
Acknowledgements
This research is a part of the project (No. 31007) funded by Ministry of Science and Technological
Development, Republic of Serbia.