## 3 Results and Discussion
### Effects of Waxy Barley Bran Blend Ratio
#### 3.3.4 Textural Properties  
The textural properties of the breads obtained with different substitutions are shown in Figure 6. Hardness stress was highest in the bread with 30% OBLP replacement group (11,277.50 Pa), followed by those in bread with 50% IBLP replacement (677.50 Pa), con trol group (3060.00 Pa), 30% IBLP replacement (1935.00 Pa), and 10% IBLP replacement (767.50 Pa) groups. Significant differences in hardness stress were observed between the 30% OBLP and 50% IBLP replacement groups compared to that in the control group and between the 30% and 10% IBLP replacement groups (_p_ < 0.05). However, the values were comparable in 30% IBLP, 10% IBLP, and control groups. Cohesiveness was the highest in the 10% IBLP replacement group (0.80), followed by the 30% IBLP (0.73), 30% OBLP (0.70), 50% IBLP replacement (0.68), and control (0.62) groups, with a significant difference observed between the 10% IBLP replacement and  
Figure 6: Effect of waxy barley bran on hardness stress (**a**), cohesiveness (**b**), and gumminess stress (**c**) of bread after baking. Bars represent the mean \(\pm\) standard error (\(n\) = 10). Different letters (a–d) indicate significant differences (_p_ < 0.05). IBLP—inner bran layer powder; OBLP—outer bran layer powder. control groups (\(p<0.05\)). In contrast, no significant difference in cohesiveness was observed between the other groups. Gumminess stress was the highest in OBLP 30% replacement group (7894.04 Pa), followed by IBLP 50% replacement (4597.77 Pa), control (1867.46 Pa), IBLP 30% replacement (1412.64 Pa) and IBLP 10% replacement (615.35 Pa) groups. As with cohesiveness, gumminess stress showed no significant difference between the IBLP 30% replacement and control groups or the IBLP 10% replacement group. However, it differed significantly between the OBLP 30% and IBLP 50% replacement groups (\(p<0.05\)). The IBLP 10% replacement group exhibited the lowest hardness and gumminess stress, indicating a softer texture. Conversely, the IBLP 50% and OBLP 30% replacement groups demonstrated higher hardness and gumminess stresses, indicating a firmer texture. These textural characteristics align with the observations of the bread's appearance, height, and specific volume. The breads in the 10% IBLP replacement group exhibited softer crumbs, likely due to thinner crumb walls surrounding the air spaces and a higher specific volume. In contrast, those in the IBLP 50% and OBLP 30% replacement groups had thicker crumb walls and denser crumb tissue, contributing to a harder texture (Figure 3). This increased hardness may be attributed to the denser crumb structure [57]. [PERSON] et al. (2015) [58] also reported that the increase in crumb stiffness is mainly due to the increase in density caused by the addition of bran and that density during fermentation is improved by the addition of gluten. This may be due to bran particles destabilizing the bubble interface of the fermented dough, promoting bubble coalescence and collapsing the dough [58]. Other possible influences included \(\beta\)-glucan and polyphenols. [PERSON] et al. (2024) [59] reported that when oat \(\beta\)-glucan (O\(\beta\)G) and tea polyphenols (TPs) were at low concentrations (O\(\beta\)G: 1 g/100 g, TP: 0.5 g/100 g), the extensibility of the bread dough was higher, while at high concentrations (O\(\beta\)G: 5 g/100 g, TP: 2 g/100 g), the opposite was found. The high extensibility of dough is suitable for making soft-textured products [60]. The reason why the extensibility of dough decreases when the content of \(\beta\)-glucan is high is thought to be due to the high viscosity of \(\beta\)-glucan [61]. Furthermore, at appropriate concentrations, TP binds to proteins through non-covalent forces such as hydrogen bonds with amino, hydroxyl, and carboxyl groups of proteins, strengthening the gluten network [62]. On the other hand, excessive TP concentration may reduce disulfide bonds and disrupt the network [63; 64].