## 3 Results and Discussion
### Functional Characteristics of T. catapa and Its Blends with Erythritrol and Cane Sugar
catappa_ and its erythroid and cane sugar blends. Water absorption capacity (WAC) values ranging from 2.33 to 2.65 g/g are similar to those reported by [PERSON] et al. (2021) [27] for _T. catappa_ seed flour. In the study by [PERSON] et al. (2019) [28], adding sweeteners such as erythroid and stevia reduced the water absorption of dough. The authors suggest the behavior occurs because sweeteners reduce the content of protein and complex carbohydrates, which are responsible for binding water in the dough; however, a more reasonable explanation suggests that the reduction in water absorption is due to the sweeteners' competition for water with proteins and complex carbohydrates, rather than a direct reduction in their content within the dough. The oil absorption capacity (OAC) values (1.61-1.91 g/g) suggest moderate lipid-binding capabilities, which are essential for food applications. These values are comparable to those in other tropical nut flours [29]. The high oil binding capacity of _T. catappa_ is confirmed by the results of [PERSON] et al. (2019) [30], where the oil absorption capacity increased with increasing levels of _T. catappa_ flour in blends. The OAC in food is due to oil retention in the polar chains of proteins. The higher protein and fat content in _T. catappa_ samples compared to 100% starch samples promoted more lipid-lipid, lipid-protein interactions, resulting in a higher OAC. According to [PERSON] et al. (2013) [31], the ability of proteins in a food sample to retain fat is an important quality feature because fat acts as a flavor carrier and thus increases palatability. The hydrophilic-lipophilic index (HLI) values (1.35-1.51) indicate balanced water and oil binding properties, making the flour suitable for various food applications. The water solubility index (WSI) values (14.69-23.19%) suggest good solubility characteristics, while the swelling power (SP) values (3.63-3.95) indicate moderate swelling capacity, which is advantageous for baked products. The foaming and emulsification characteristics of _T. catappa_ powder and its blends with erythritol and cane sugar are presented in Table 2. Foaming capacity (FC) values slightly decreased with increasing sweetener content, ranging from 51.73 \(\pm\) 0.02 to 53.21 \(\pm\) 0.73%. The highest FC was observed in pure _T. catappa_ (53.21 \(\pm\) 0.73%), while the 15% cane sugar blend showed the lowest value (51.73 \(\pm\) 0.02%). The 5% erythroid and 5% cane sugar blends exhibited intermediate values of 52.64 \(\pm\) 0.01% and 52.39 \(\pm\) 0.73%, respectively. Foam stability (FS) values remained relatively consistent across all samples, ranging from 103.2 \(\pm\) 3.1 to 105.2 \(\pm\) 0.0%, with no statistically significant differences. Interestingly, all blends showed slightly higher FS values compared to pure _T. catappa_, suggesting that the addition of sweeteners might contribute to foam stabilization, which is confirmed by the results of the research by [PERSON] et al. (2020) [32], where the addition of erythroid to foam created from whey protein isolate improved the stability of the foam, but reduced its volume. Erythritol increases the viscosity of the solution, which slows down the liquid drainage from the foam and prevents it from collapsing, slightly increases the surface tension of solutions, and in combination with protein, creates a more stable structure at the water-air interface.