# Features of Bread Made from Different Amaranth Flour Fractions Partially Substituting Wheat Flour
## 4 Discussion
### Influence of PS and AF Addition Level on Falling Number, Mixolab, and Alveographic Parameters
Some authors reported that the greater milling damage to the starch level in superfine-ground flour gave rise to a decrease in total gas production during dough fermentation [50] due to the amylase inactivation, thus hindering the formation of fermentable sugars and reducing the capacity of yeasts to produce gas [51]. The compact particles of the flours produced dough with high consistency and bread with volume and textural properties lower than those obtained with large particles. These changes might be due to the competitiveness of water uptake between wheat gluten and AF components such as starch, protein, and fiber. The highest swelling capacity value was found for the small AF particle size due to an increase in damaged starch, which influences dough behavior [3]. Fundamental rheological tests can offer valuable information about the final product. An increase in elastic (G\({}^{\prime}\)) and viscous (G\({}^{\prime\prime}\)) moduli values could be linked to the presence of binding agents from the composite dough and attractive forces between starch granules and amaranth fibers, this trend suggesting a solid, elastic-like behavior of the WF-AF composite dough. The higher values of G\({}^{\prime}\) and G\({}^{\prime\prime}\) could probably also be a result of interactions between proteins and the formation of a protein-starch complex. The significant increase in G\({}^{\prime}\) with the increased addition level of AF to wheat flour could be related to the increasing amounts of damaged starch in the composite flour. [PERSON] et al. [52] found that the damaged starch in wheat flour greater affected the viscoelastic properties of noodles than the particle size, resulting in stiffer doughs, than did flour with low starch damage. Decreases in loss tangent (tan \(\delta\)) values are typical for elastic and firm doughs. Similar results were found by [PERSON] et al. [53]. The tan \(\delta\) values are influenced by the level of starch damage. The dough from flours with high starch damage presents significantly lower values than those with low or medium starch damage [52]. A decrease in the maximum gelatinization temperature with the increase in the AF addition could be due to the higher amount of water absorbed by the amaranth grain, and the greater swelling power and solubility of the amaranth starch granule compared with the wheat starch granule [54]. A higher amount of water absorbed could be related to the starch damage from the amaranth flour milling process. The maximum creep compliance (Jc\({}_{\text{max}}\)) and the maximum recovery compliance (Jr\({}_{\text{max}}\)), measured at the end of the creep and recovery phases, respectively, represent the principal characteristics from the creep-recovery curves. The results of the creep-recovery measurements are significantly influenced by the protein or starch levels from amaranth fractions, while the AF addition level did not significantly affect these dynamic parameters. This strengthening phenomenon can be related to the hydroxyl groups from sugar compounds from amaranth seeds, which may directly interact with proteins, resulting in non-covalent or covalent bonding. Protein-polyphenol interactions modify proteins, influencing the quality and functional properties of a food [23; 55]. The bread volume decreased as the AF addition level was increased, which could be explained by the poor baking quality of this flour, due to its lack of gluten proteins, which are present in wheat [25]. The proteins present in amaranth flour consist of three major fractions, albumins (51%), globulins (16%), and glutelins (24%), and a minor, alcohol-soluble fraction, prolamine, between 1.4 and 2.0% [56; 57]. The albumin fraction is comparable with egg-white proteins and can be used as an egg substitute in different products [25]. The decrease in bread volume with the AF addition can be linked to the weakening of the gluten matrix and reduced gas retention of the dough (Table 4), which is predictable for the higher dough tenacity and lower extensibility (Table 3).