## 3 Results and Discussion
### Fatty Acid Composition  
Table 3 shows the improvements in the fatty acid profile achieved in the reformulated samples, due to the substitution of butter, which mainly contains palmitic acid, with nut oils, which are sources of unsaturated fatty acids. As expected, the highest value of palmitic acid, a saturated fatty acid (SFA), was found in the control sample. This value decreased as the percentage of oils increased. Notably, the samples with 100% almond and walnut oil reduced the palmitic acid content by approximately 70%. Similarly, the research [41] achieved a reduction in palmitic acid by up to 2.74 times in cookies, where butter and margarine were replaced with olive oil. This fatty acid makes up a significant portion of the fatty acids in traditional brownies. Ref. [42] managed to reduce this type of fatty acid by 74% in muffins by substituting butter with monoglyceride-based oleogels, which was very similar to the behavior observed in this study. Regarding SFAs, they have been of great interest in many studies due to their association with health, as they stimulate pro-inflammatory mechanisms through reactive oxygen species [43]. Additionally, a high consumption of saturated fats has been linked to an increased risk of cardiovascular disease, prompting regulatory bodies to recommend reducing their intake, specifically ensuring that these fats do not exceed 10% of daily intake [42]. As can be observed in the case of polyunsaturated fatty acids, the results are very positive in all cases, as their content increases in every sample. The case of monounsaturated fatty acids is different, as the use of walnut oil resulted in a decrease in content compared \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 Pamitic acid (\%) & 36.10 \(\pm\) 0.23 a & 21.60 \(\pm\) 0.98 a & 23.40 \(\pm\) 0.12 b & 21.20 \(\pm\) 0.34 c & 10.00 \(\pm\) 0.77 a & 14.30 \(\pm\) 0.12 d & 11.40 \(\pm\) 0.67 e \\ Stearic acid (\%) & 14.10 \(\pm\) 0.36 a & 9.65 \(\pm\) 0.45 b & 9.08 \(\pm\) 0.14 b & 9.94 \(\pm\) 0.56 b & 6.34 \(\pm\) 0.11 c & 5.59 \(\pm\) 0.14 d & 6.74 \(\pm\) 0.56 c \\ Oleic acid (\%) & 28.70 \(\pm\) 1.23 c & 49.50 \(\pm\) 0.45 c & 42.20 \(\pm\) 0.22 d & 2.50 \(\pm\) 0.19 d & 65.80 \(\pm\) 0.34 a & 51.70 \(\pm\) 0.22 b & 21.00 \(\pm\) 0.19 d \\ Linoleic acid (\%) & 4.74 \(\pm\) 0.53 f & 11.50 \(\pm\) 1.02 e & 17.30 \(\pm\) 0.23 d & 31.30 \(\pm\) 0.21 b & 16.06 \(\pm\) 0.61 d & 26.30 \(\pm\) 0.23 c & 50.20 \(\pm\) 0.21 a \\ Linoleic acid (\%) & 0.43 \(\pm\) 0.22 c & 0.21 \(\pm\) 0.45 c & 0.40 \(\pm\) 0.34 d & 5.56 \(\pm\) 0.31 b & 0.10 \(\pm\) 0.36 c & 0.42 \(\pm\) 0.34 c & 9.71 \(\pm\) 0.3 a \\ SA (\%) & 63.82 \(\pm\) 0.18 a & 37.35 \(\pm\) 0.31 b & 38.04 \(\pm\) 0.32 c & 36.98 \(\pm\) 0.56 b & 16.75 \(\pm\) 0.21 c & 20.25 \(\pm\) 0.15 b & 18.60 \(\pm\) 0.68 c \\ MUFA (\%) & 30.99 \(\pm\) 1.12 c & 50.84 \(\pm\) 0.28 b & 43.89 \(\pm\) 0.45 c & 26.15 \(\pm\) 0.61 d & 66.52 \(\pm\) 0.78 c & 53.04 \(\pm\) 0.37 b & 21.49 \(\pm\) 0.54 d \\ PUFA (\%) & 5.17 \(\pm\) 0.22 c & 11.71 \(\pm\) 0.31 c & 17.70 \(\pm\) 0.28 c & 36.86 \(\pm\) 0.12 c & 16.70 \(\pm\) 0.34 d & 26.72 \(\pm\) 0.88 c & 59.91 \(\pm\) 0.36 c \\ Vitamin E (mg/kg) & \textless\_2.50 \(\pm\) 0.12 d & \textless\_2.50 \(\pm\) 0.24 d & \textless\_2.50 \(\pm\) 0.28 d & 4.43 \(\pm\) 0.17 c & 6.74 \(\pm\) 0.34 b & 5.3 \(\pm\) 0.28 b & 8.35 \(\pm\) 0.17 a \\ TBA (mg MDA/kg) & 0.91 \(\pm\) 0.21 & 0.79 \(\pm\) 0.34 & 0.88 \(\pm\) 0.45 & 0.91 \(\pm\) 0.28 & 0.81 \(\pm\) 0.12 & 0.82 \(\pm\) 0.45 & 0.91 \(\pm\) 0.28 \\ \hline \hline \end{tabular}  
* The numbers represent the mean \(\pm\) standard deviation. Different letters in the same row for each attribute indicate significant differences (\(\rho<0.05\)).  
\end{table} 
Table 3: Fatty acid, vitamin E, and TBA profile of brownies reformulated with pistachio, almond, and walnut oils. to the control sample.