## 3 Results and Discussion
### Sensory Analysis  
The effects of the addition of different amounts of pecan nuts on the sensory evaluation of lamb burgers are shown in Figure 1. A sensory evaluation of lamb burgers revealed no significant difference in any sensory attributes between the control and treated burgers, except colour. Variations in the colour of meat products have been associated with the ingredients, the contents of water, fat and the type of package used.  
\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}  & & \multicolumn{1}{c}{**5\%**} & & & \multicolumn{1}{c}{**10\%**} & & \\ \hline Antioxidant composition (\(\mu\)g g\({}^{-1}\)) & & & & & & \\ \(\alpha\)-tocopherol & 4.21 b & 4.97 ab & 4.57 ab & 5.31 a & 0.14 & 0.019 \\ \(\gamma\)-tocopherol & 0.16 d & 11.18 b & 18.64 b & 27.74 a & 1.84 & 0.000 \\ AAT & 0.65 c & 0.71 c & 0.82 b & 0.96 a & 0.02 & 0.000 \\ Oxidative status & & & & & & \\ Lipid oxidation (\(\mu\)g MDA g\({}^{-1}\)) & 1.46 a & 0.59 b & 0.59 b & 0.58 b & 0.07 & 0.000 \\ Protein oxidation (nmol & & & & & & \\ carbonyls mg proteins g\({}^{-1}\)) & & 2.26 a & 1.56 b & 1.73 ab & 2.13 ab & 0.09 & 0.013 \\ \hline \hline \end{tabular} a, b, c, d: different letters in the same row indicate significant differences during storage according to Tukey’s HSD test; values are expressed as means. \(\alpha\)- and \(\gamma\)-tocopherol are expressed as mg/kg DM; AAT: total antioxidant activity.  
\end{table}
Table 6: Antioxidant composition and oxidative status of raw Merino lamb burgers with different amounts of pecans in their formulation.  
\begin{table}
\begin{tabular}{l 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 Mesophilic aerobic & 5.41 & 5.05 & 5.09 & 5.03 & 0.07 & 0.188 \\ bacteria & 2.38 & 2.22 & 2.01 & 2.22 & 0.07 & 0.320 \\ Lactic acid bacteria & 2.85 a & 2.71 a & 2.34 b & 2.79 a & 0.06 & 0.000 \\ _P. aeruginosa_ & 1.46 & 1.22 & 1.52 & 1.03 & 0.28 & 0.941 \\ _E. coli_ & ND & ND & ND & ND & - & - \\ _Salmonella_ spp. & absence & absence & absence & absence & - & - \\ \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. ND: not detected.  
\end{table}
Table 7: Microbial growth (log10 CFU/g) of raw Merino lamb burgers with different amounts of pecans in their formulation.  
The score for colour intensity of the burgers made with pecan nuts was higher (\(p<0.01\)) than that of the control burgers. On the other hand, Reyes-Padilla et al. [36] reported that all sensory attributes were affected by the addition of natural ingredients, such as pecan nuts, to low-fat bologna-type meat products. Likewise, Serrano, Cofrades and Jimenez-Colmenero [64] stated that the addition of walnuts had some effects on the sensory quality of restructured steak. Non-significant differences were found in the preference test on cooked burgers (\(p\geq 0.05\)), which indicated that preferences were similar among the four treatments (Figure 2). However, Lutz, Morales, Sepulveda and Salvina [65] reported that the use of ingredients rich in antioxidants and omega-3 fatty acids in traditional Chilean dishes improved sensory acceptance among the elderly. In contrast, for raw packaged burgers, 91.67% of the panellists chose the control burgers as their first choice, while 8.33% opted for the hamburgers made with 10% pecans (\(p<0.001\)).