## 3 Results and Discussion
### 3.3. Bread Characterization
#### 3.3.2. Bread Volume
[PERSON] et al. [82] added chickpea flour obtained from grains, germinated and fermented, in a proportion of 5%, 10%, and 15% to wheat flour. For some additions they obtained increases in the volume of bread loaves compared to the control (1560 mL), for example, an increase up to 1657 mL for the addition of 5%, 1598 mL for 10%, and 1627 mL for 15% chickpea flour; 1667 mL for 5% and 1587 mL for 10% germinated chickpea flour; and 1710 mL for 5% and 1680 mL for 10% fermented chickpea flour. For the rest of the additions, the specific volume was lower than the control. Most of the volume increases were small because the addition of chickpea flour resulted in a stickier dough that was more difficult to process, especially in the case of sprouted chickpeas, due to the reduced content of gluten-forming proteins. The bread obtained was generally more compact, with a denser structure [82]. In a similar study, [PERSON] et al. [83] added chickpea flour from raw and extruded grains in 15% and 30% proportions. They recorded a decrease in volume for all additions compared to the control. The reduction in volume was higher for the 30% addition compared to 15%, and the reduction in volume was also higher for the flour from extruded chickpea grains due to the decrease in the content of gluten-forming proteins even if the total protein content of the flour mixes increased. [PERSON] et al. [48] stated that the addition of fibre dilutes proteins and interferes with forming the optimal gluten network, confirming the previous statements. [PERSON] et al. [84] continued these studies by combining chickpea flour with emulsifiers. If no emulsifier was added to the white bread, the specific volume of the bread was significantly smaller (\(p<0.05\)). Therefore, they stated that only emulsifiers significantly affected the specific volume of white bread (\(p<0.05\)). The decrease in bread volume caused by chickpea flour can be counteracted by increased water in the dough. In wholemeal bread, the volume increase is influenced by a combined effect of water and emulsifiers [84]. In general, bread volume is correlated with a soft texture and high porosity, while bread density refers to a more compact, harder-textured bread [84]. The inverse of the density, expressed in g/cm\({}^{3}\), is the specific volume in cm\({}^{3}\)/g. This parameter results from the calculation that relates the total volume of a loaf of bread to its mass, and it presents the same evolution as the volume of bread. Thus, bread with the addition of Rp had higher values of the specific volume than the control, except for the 0.5% addition of Rp. [PERSON] et al. [85] reported a slight increase in the specific volume of bread obtained from wheat flour with the addition of 10% and 20% barley flour with a low proportional coating content for smaller mesh sizes, thus retaining more coating particles with the addition of guar gum. The highest value of the specific volume was obtained for sieve 40 with the addition of 1% guar gum (2.90 \(\pm\) 0.20 cm\({}^{3}\)/g) compared to the control (2.70 \(\pm\) 0.17 cm\({}^{3}\)/g), and was lower for sieve 50 with the addition of 20% barley flour with a low coating content, without the addition of guar gum (2.10 \(\pm\) 0.17 cm\({}^{3}\)/g). Instead, [PERSON] et al. [78] obtained a specific volume reduction from 1.7 cm\({}^{3}\)/g to 1.4 cm\({}^{3}\)/g when adding 50% to 65% sweet potato flour. In other studies, higher specific bread volumes were reported, for example, 3.3-4.0 cm\({}^{3}\)/g for bread prepared with the addition of heat-treated maitake mushroom powder [86], and 3.4-4.4 cm\({}^{3}\)/g for wheat bread with added dextrins [87].