## 3 Results and Discussions  
### Parameters of the Laboratory Baking Process  
Table 1 shows the results regarding the parameters of the laboratory baking process for the developed wheat bread, in which the flour was replaced with walnut leaf powder (WLs). It was found that the average dough yield was 162%, and the value of this parameter did not depend statistically significantly on the amount of powdered walnut leaves added (\(p\) \(\geq\) 0.05). However, the inclusion of WLs in the bread recipe had a significant impact on the value of baking loss because the highest value of this parameter was recorded in dough with a 2.5% share of WLs. Moreover, this dough was also characterized by the highest value of total baking loss (Table 1). Bread yield is an important technological parameter that also determines the profitability of production. It was shown that the partial replacement of wheat flour with the discussed additive usually resulted in a small but statistically significant increase in bread yield (\(p\)\(\leq\) 0.05). A similar tendency to change the laboratory baking process parameters was observed in earlier work, in which wheat flour was replaced with dried walnut flowers [16]. The highest value of this parameter was found in bread with 2.0% WLs (Table 1). The research found, among other things, a significant positive linear correlation between the values of parameters showing dough yield and bread yield (\(r\) = 0.88, \(p\) < 0.05), oven loss and total baking loss (\(r\) = 0.97, \(p\) < 0.05). The volume of bread is a physical parameter significantly related to the degree of consumer acceptability. According to [PERSON] et al. [30], the volume of a loaf of bread indirectly informs us about the consistency of the dough, the course of fermentation, aeration and the porosity of the crumb. It was shown that replacing flour with WLs powder resulted in a significant decrease in the volume of leaves (\(p\leq 0.05\)) of the tested wheat bread (Table 1). The control bread had the largest volume, and the bread with a 2.5% WLs content had the smallest volume (420 cm\({}^{3}\)). This volume difference was significant and visually noticeable (Figure 1). This is consistent with observations from our previous work [16], where wheat bread was enriched with dried walnut flowers. The reason for the reduction in the volume of the loaves of the enriched bread is probably the weakening of the gluten network built during kneading the dough. As a result, the CO\({}_{2}\) from the fermentation process is not fully retained because the more of this gas retained, the softer and more flexible the crumb is, and the greater the volume. The relationship between the volume of the loaves and their weight is expressed as the specific volume. It was shown that the specific volume of the control bread was 2.44 g/cm\({}^{3}\), which may be due to the activity of yeast, the conditions of the fermentation action or the quality of the recipe ingredients. The research showed that breads containing WLs were characterized by a statistically significantly lower value of this parameter compared to the control sample (\(p\leq 0.05\)), and the specific volume decreased as the share of walnut leaves in the recipe of the tested breads increased. The statistical analysis performed showed a strong positive correlation between the volume and the specific volume of the loaves (\(r=0.99\), \(p<0.05\)). According to other researchers [31; 32], the average specific volume of wheat bread was from 3.5 to 5.0 g/cm\({}^{3}\). In the case of gluten-free bread, it is usually about 2 g/cm\({}^{3}\). According to [PERSON] et al. [32], specific volume is one of the most important technological indicators proving the quality of bread, but it is not the only or most important one. Equally important is the porosity of the crumb, which is measured by the uniformity of the distribution and the size of the gas bubbles that create the crumb structure.