## 3 Results and Discussion
### The Thermo-Mechanical Properties of the Composite Flows
[PERSON] and [PERSON] [13] reported water holding capacity values of 1.29-1.35 mL/g for PP. They highlighted that the water-related properties of the proteins are influenced by intrinsic and extrinsic properties like structural properties of the proteins, namely, amino acid composition, conformation particularities, and surface hydrophobicity, protein concentration, temperature, pH, and ionic strength [13]. Regarding the particular influence of the secondary structure elements, [PERSON] et al. [14] indicated that the \(\alpha\)-helical content is mainly responsible for the viscosity of the dough. Analyzing the secondary structure of proteins from pumpkin seed protein isolates, [PERSON] et al. [35] observed the presence of 38.2% \(\alpha\)-helix conformation, while [PERSON] and [PERSON] [13] reported, for the water-soluble fraction in the protein isolate, the presence of 38.8% \(\alpha\)-helical content, whereas the rest of the amino acids were organized as \(\beta\)-strands (17.7%), turns (8.4%), or random coils (35.0%). One could assume that kneading and the heat treatment resulted in structural changes in the proteins, causing the TMWT to increase from 42.15 to 47.52% in the case of the dough with a WA level of 70% and from 34.01 to 43.77% for the samples with a WA level of 75% (Table 3). Mechanical action, combined with the temperature increase, most likely caused disulfide bonds' breaking, therefore exposing more sulfhydryl groups on the surface of the protein molecules. It should be noted that the C2 value was obtained at a temperature of about 53 \({}^{\circ}\)C, which was higher compared to that required for the RF + OFF composite flour, for which C2 was obtained at 49-50 \({}^{\circ}\)C.  
Figure 2: Mixolab curve of the dough samples prepared with composite flour consisting of 80% rice flour + 20% oat flake flour (RF + OFF) and 65% rice flour + 20% oat flake flour + 15% pumpkin seed protein powder (RF + OFF + PP). Measurements were carried out at water absorption (WA) levels of 70 (**a**) and 75% (**b**). Compared to the RF samples, the addition of OFF produced small effects on C3 but significantly decreased the (C3-C2) and increased the (C3-C4) (\(p<0.05\)). These changes were due to the properties of starch and non-starch polysaccharides from the OFF. The dough with a WA level of 70% had higher C5 and (C5-C4) values compared to the sample with a WA of 75%. One could estimate that, in the dough prepared with 70% WA, the amount of water was insufficient to well hydrate the flour matrix rich in non-starch polysaccharides originating from the OFF. The addition of OFF also produced important changes in the gelatinization temperature, which decreased from 84-86 \({}^{\circ}\)C to 76 \({}^{\circ}\)C upon substituting 20% of the RF with the OFF. The addition of PP decreased the C3, (C3-C2), and (C3-C4) values compared to the RF + OFF (Tables 2 and 3). The C3 decrease could also be attributed to the high lipid content of the PP (Table 1) but also to starch dilution by substituting 15% RF with the PP [4]. [PERSON] and [PERSON] [4] reported a 23% decrease in C3, from 0.82 to 0.63 Nm, by substituting 13% RF with soy protein isolate at 95% WA. In the case of our experiment, the RF substitution with 15% PP resulted in a smaller C3 decrease, from 1.95 to 1.85 Nm, in the case of the dough prepared with a WA level of 70%, and from 1.81 to 1.66 Nm in the case of the samples with a WA level of 75%. These observations are in good agreement with [PERSON] et al. [36], who reported on the higher strength of the gel based on native pumpkin seed protein isolate compared to soybean or pea protein isolates. PP addition to the RF + OFF composite flour caused a significant decrease in C5 and (C5-C4) (Tables 4 and 5), which may be a good premise for using this high protein content composite flour for obtaining bakery products.