*3.4. Characteristics of the Quality of Bread*

The weight loss, specific volume, pH-value, and moisture content of various breads are presented in Table 6.


**Table 6.** Basic properties of wheat bread and gluten-free bread with and without added by-products.

DOP: dried orange pomace; DAP: dried apple pomace; DTP: dried tomato peel; DPP: dried pepper peel; DPPP: dried prickly pear peel; DPPSP: dried prickly pear seed peel; CTRL: control; GF: gluten-free; WL: weight loss; V*sp*: specific volume; *P: p*-value probability; *F*: F-value Fishera-o letters indicate a statistical different of means in the same column (*p* < 0.05).

#### 3.4.1. Weight Loss

Table 6 shows that the weight loss was greater for all formulas compared to the glutenfree control bread (*p* < 0.05). There was no significant difference in the weight loss values of bread containing different amounts of DPP and DPPSP by-products. The weight loss of gluten-free bread increased with increasing levels of DOP, DAP, and DPPP, but decreased with increasing levels of DTP. At high DOP, DAP, or DPPP values, the water cannot be retained in the bread. This may be due to the water-holding capacity of the by-products. Weight loss before and after baking of bread is generally specifically associated with water loss. The addition of pre-hydration by-products increased the water loss during baking, which increased the weight loss of the bread [52]. Compared to the gluten-free control bread, the percent weight loss was greater for the wheat control bread, the DOP bread, and the DAP bread at 5% and 7.5% additions. Furthermore, DOP bread with 2.5% addition resulted in little weight loss (18.33%). Regarding the WL results, the samples with DPPP proved to be more effective in reducing weight loss (19.05–22.76%). In the study of Milde, Ramallo [74], low weight loss was sought to ensure a moisture content that impeded the dehydration of bread and to reduce the hardness.
