## 3 Results and Discussion
### Determination of the Fatty Acid Profile  
As expected, the addition of pecan nuts in the burger formulations resulted in significant differences in their fatty acid profiles (Table 5). Palmitic acid and stearic acid values decreased as the amount of pecan nuts in the formulation increased (\(p<0.001\)), while in contrast, oleic, linoleic and linolenic acid values increased (\(p<0.001\)). The meat of ruminants is generally rich in SFAs [37]. The reduction in major saturated fatty acids resulted in a significantly lower SFA content in burgers with pecans than in the controls (\(p<0.001\)). In addition, the MUFA and PUFA levels in burgers with pecans were increased relative to the values obtained for the control samples. (\(p<0.001\)). According to the results, this increase in PUFAs was mainly caused by linoleic acid, since its content was more than doubled in the burgers made with pecan nuts compared to the control burgers. Although pecan nuts have a high fat content, they have a fatty acid profile that is beneficial for health due to their high content of unsaturated fatty acids, mainly oleic acid [51; 52]. Oleic acid has been shown to have a beneficial effect against cancer and inflammatory diseases [53], and its high content in lamb burgers made with pecan nuts should be considered beneficial for human health. Linoleic acid (C18:2n6) has been found to be the most abundant PUFA in pecan nuts and, additionally, pecan nuts contain a small amount of alpha-linolenic acid (C18:3n3) [52]. Omega-6 linoleic acid and omega-3 alpha-linolenic acid are essential fatty acids that cannot be synthesized endogenously by most animals; therefore, their constant dietary intake is essential. Besides the evaluation of the fatty acids, the nutritional quality of the fatty acid profile can be evaluated using nutritional quality indexes, such as the PUFA/SFA ratio and the atherogenic and thrombogenic indexes (Table 5). Considering the improvement in the fatty acid profile of burgers with different concentrations of pecans, these batches showed better nutritional quality indexes than the control. According to nutritional recommendations, the optimal PUFA/SFA ratio is 0.4 [37; 54]. In this research, Pecan15 burgers obtained a value of 0.37, which is very close to the optimum value of 0.4 for preventing some coronary disorders, although the rest of the batches ob \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & \multirow{2}{*}{**Control**} & \multicolumn{4}{c}{**With Pecans**} & \multirow{2}{*}{**SEM**} & \multirow{2}{*}{**\(p\)-Value**} \\ \cline{3-3} \cline{5-6}  & & **5\%** & **10\%** & & **15\%** & \\ \hline Shear/Compression force & & & & & \\ Hardness (N) & 38.29 & 36.93 & 32.96 & 33.29 & 7.34 & 0.387 \\ TPA 50 & & & & & & \\ Hardness(N/cm\({}^{2}\)) & 19.20 & 13.91 & 14.05 & 14.89 & 4.54 & 0.055 \\ Springiness (cm) & 0.85 a & 0.81 ab & 0.81 ab & 0.75 b & 0.07 & 0.022 \\ Cohesiveness & 0.66 a & 0.69 a & 0.62 a & 0.53 b & 0.08 & 0.000 \\ Gumminess (N cm s\({}^{2}\)) & 12.64 a & 9.56 ab & 8.77 ab & 8.20 b & 3.32 & 0.027 \\ Chewiness (N cm s\({}^{2}\)) & 10.74 a & 7.90 ab & 7.07 b & 6.33 b & 2.99 & 0.011 \\ \hline \hline \end{tabular} a, b: different letters in the same row indicate significant differences during storage according to Tukey’s HSD test; values are expressed as means. TPA: texture profile analysis.  
\end{table} 
Table 4: Instrumental textural properties of cooked Merino lamb burgers with different amounts of pecans in their formulation. tained values lower than the recommended value. However, other authors [55] noted that the PUFA/SFA index did not consider the effects of MUFAs and took into account that all SFAs were affected in the same way in terms of cholesterol increase. In this sense, other nutritional indexes, such as atherogenic (AI) and thrombogenic indexes (TI), are also used to measure the propensity of a diet or food to influence the likelihood of coronary heart disease.