## 3 Results and Discussion  
### Physical Parameters  
All texture parameters were statistically different when butter was replaced with seed oil. The results are shown in Table 1. The hardness of the brownies decreases as the butter content is reduced, with the control sample showing the highest values [24]. This is because butter is rich in saturated fatty acids, which are responsible for its solid texture. In contrast, when non-emulsified oils, which have a liquid texture at room temperature, are used, a softer texture is obtained. However, as observed in other studies, consumers do not give negative scores for texture when they try the product [25]. This could be minimized by using oleogels, as depending on the type of emulsion developed, the hardness may not be affected [26]. The elasticity decreased by 33.3% and 55.5% after replacing 50% of the butter with almond and walnut oils, respectively, and increased after replacing 100% of the butter with nut oils, particularly by 59.2% for walnut oil. Regarding cohesiveness, it increased by 31.3% and 7.4% in the almond and walnut oils replaced at 50%, respectively, while it decreased by 16.4% and 26.8% in the pistachio oil at 50% and walnut oil at 100%, respectively. As for gumminess, calculated as the product of hardness and cohesiveness, it decreased in all cases, with a maximum reduction of 70% for the brownie m \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Parameter** & **Control** & **Almond** & **Pistachio** & **Walnut** & **Almond** & **Pistachio** & **Walnut** \\  & **50\%** & **50\%** & **50\%** & **100\%** & **100\%** & **100\%** \\ \hline Hardness & 74.23 \(\pm\) 2.97 \({}^{\text{a}}\) & 49.41 \(\pm\) 1.82 \({}^{\text{b}}\) & 46.02 \(\pm\) 1.81 \({}^{\text{kc}}\) & 42.59 \(\pm\) 1.48 \({}^{\text{c}}\) & 36.71 \(\pm\) 1.40 \({}^{\text{d}}\) & 26.11\(\pm\) 3.25 \({}^{\text{e}}\) & 20.96 \(\pm\) 2.64 \({}^{\text{e}}\) \\ Elasticity & 0.27 \(\pm\) 0.06 \({}^{\text{b}}\) & 0.18 \(\pm\) 0.02 \({}^{\text{c}}\) & 0.40 \(\pm\) 0.11 \({}^{\text{a}}\) & 0.12 \(\pm\) 0.01 \({}^{\text{c}}\) & 0.35 \(\pm\) 0.05 \({}^{\text{ab}}\) & 0.24 \(\pm\) 0.01 \({}^{\text{b}}\) & 0.43 \(\pm\) 0.02 \({}^{\text{a}}\) \\ Cohesiveness & 0.67 \(\pm\) 0.1 \({}^{\text{b}}\) & 0.72 \(\pm\) 0.07 \({}^{\text{ab}}\) & 0.49 \(\pm\) 0.02 \({}^{\text{c}}\) & 0.88 \(\pm\) 0.1 \({}^{\text{a}}\) & 0.61 \(\pm\) 0.06 \({}^{\text{b}}\) & 0.65 \(\pm\) 0.04 \({}^{\text{b}}\) & 0.56 \(\pm\) 0.05 \({}^{\text{c}}\) \\ Gumminess & 48.68 \(\pm\) 1.05 \({}^{\text{a}}\) & 35.63 \(\pm\) 1.21 \({}^{\text{b}}\) & 14.62 \(\pm\) 1.07 \({}^{\text{c}}\) & 19.11 \(\pm\) 1.91 \({}^{\text{de}}\) & 24.04 \(\pm\) 1.56 \({}^{\text{c}}\) & 21.01 \(\pm\) 0.54 \({}^{\text{d}}\) & 24.91 \(\pm\) 0.62 \({}^{\text{c}}\) \\ Chewiness & 17.53 \(\pm\) 0.74 \({}^{\text{a}}\) & 6.79 \(\pm\) 0.72 \({}^{\text{c}}\) & 10.24 \(\pm\) 0.46 \({}^{\text{b}}\) & 10.62 \(\pm\) 0.52 \({}^{\text{b}}\) & 4.45 \(\pm\)0.39 \({}^{\text{d}}\) & 4.55 \(\pm\) 0.55 \({}^{\text{d}}\) & 2.54 \(\pm\) 0.16 \({}^{\text{e}}\) \\ \hline \hline \end{tabular}  
* The numbers represent the mean \(\pm\) standard deviation. Different letters in the same row for each attribute indicate significant differences (\(p<0.05\)).  
\end{table} 
Table 1: Texture parameters analyzed in brownie samples with a replacement of 50 and 100% butter with nut oils. Regarding chewiness, which is the energy required to chew solid foods, the lowest values were obtained in the case of 100% replacement with nut oils. In general, the values for hardness, gumminess, and chewiness showed a similar trend, with the control sample having the highest values, meaning it requires more energy to chew until complete swallowing [27]. Additionally, the studies by [27; 28], which used fat substitutes for the preparation of cakes and brownies, respectively, showed similar results to those obtained in this study. The colorimetric parameters, both for the dough and the baked brownies, are shown in Figures 2 and 3.