## 3 Results and Discussion
### Oxidation Shelf-Life Study of Beef Burgers
\begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{4}{c}{**Days of Storage**} \\ \cline{2-5}  & **0** & **1** & **3** & **Cooked** \\ \hline pH & & & & \\ CB & 5.92 \(\pm\) 0.01 a,w & 5.32 \(\pm\) 0.02 c,y & 5.29 \(\pm\) 0.02 d,y & 5.78 \(\pm\) 0.06 a,x \\ FRB & 5.46 \(\pm\) 0.01 c,x & 5.42 \(\pm\) 0.02 b,x & 5.32 \(\pm\) 0.01 c,y & 5.78 \(\pm\) 0.03 a,w \\ FRB-AE & 5.58 \(\pm\) 0.02 b,x & 5.49 \(\pm\) 0.02 a,y & 5.47 \(\pm\) 0.01 a,y & 5.76 \(\pm\) 0.03 a,w \\ FRB-TAE & 5.53 \(\pm\) 0.01 d,x & 5.44 \(\pm\) 0.01 b,y & 5.43 \(\pm\) 0.02 b,y & 5.62 \(\pm\) 0.03 b,w \\ L\({}^{*}\) & 39.27 \(\pm\) 0.79 ab,x & 44.00 \(\pm\) 1.04 a,ww & 45.06 \(\pm\) 0.18 a,w & 34.44 \(\pm\) 0.17 a,y \\ FRB & 40.44 \(\pm\) 1.69 a,ww & 43.51 \(\pm\) 0.37 a,w & 45.25 \(\pm\) 0.18 a,w & 35.99 \(\pm\) 4.81 a,x \\ FRB-AE & 37.58 \(\pm\) 0.48 b,w & 39.93 \(\pm\) 0.34 b,w & 39.37 \(\pm\) 0.11 b,w & 31.84 \(\pm\) 2.04 a,x \\ FRB-TAE & 37.29 \(\pm\) 0.76 b,w & 40.34 \(\pm\) 0.24 b,w & 40.52 \(\pm\) 0.08 c,w & 34.31 \(\pm\) 4.13 a,x \\ a\({}^{*}\) & & & & \\ CB & 19.93 \(\pm\) 1.04 a,w & 21.04 \(\pm\) 0.20 a,w & 17.92 \(\pm\) 0.20 a,x & 8.44 \(\pm\) 0.11 a,y \\ FRB & 14.55 \(\pm\) 1.02 b,y & 21.66 \(\pm\) 0.45 a,x & 25.35 \(\pm\) 0.08 b,w & 7.94 \(\pm\) 0.60 a,x \\ FRB-AE & 6.76 \(\pm\) 0.42 c,w & 6.55 \(\pm\) 0.19 b,w & 5.02 \(\pm\) 0.02 c,y & 5.84 \(\pm\) 0.19 b,x \\ FRB-TAE & 6.07 \(\pm\) 0.21 c,x & 7.06 \(\pm\) 0.07 b,w & 5.23 \(\pm\) 0.25 c,y & 5.82 \(\pm\) 0.15 b,x \\ b\({}^{*}\) & & & & \\ CB & 9.22 \(\pm\) 0.37 a,y & 10.39 \(\pm\) 0.13 a,x & 9.89 \(\pm\) 0.16 a,y & 11.55 \(\pm\) 0.42 a,w \\ FRB & 8.18 \(\pm\) 0.52 a,y & 10.97 \(\pm\) 0.25 a,w & 12.14 \(\pm\) 0.06 b,w & 10.55 \(\pm\) 2.23 a,w \\ FRB-AE & 8.55 \(\pm\) 0.04 a,w & 9.41 \(\pm\) 0.33 b,w & 8.87 \(\pm\) 0.06 c,w & 8.22 \(\pm\) 2.00 a,w \\ FRB-TAE & 8.80 \(\pm\) 0.22 a,w & 11.01 \(\pm\) 0.22 a,w & 10.05 \(\pm\) 0.10 a,w & 10.58 \(\pm\) 2.43 a,w \\ AE in relation to D & & & & \\ CB & 0.00 \(\pm\) 0.00 a,y & 5.00 \(\pm\) 0.91 ab,x & 6.17 \(\pm\) 1.06 c,x & 12.68 \(\pm\) 1.12 a,w \\ FRB & 0.00 \(\pm\) 0.00 a,x & 8.22 \(\pm\) 1.47 a,w & 12.46 \(\pm\) 1.84 a,w & 8.31 \(\pm\) 3.58 a,w \\ FRB-AE & 0.00 \(\pm\) 0.00 a,x & 2.51 \(\pm\) 0.39 b,w & 2.52 \(\pm\) 0.55 b,w & 5.83 \(\pm\) 2.52 a,w \\ FRB-TAE & 0.00 \(\pm\) 0.00 a,x & 3.90 \(\pm\) 0.54 b,w & 3.57 \(\pm\) 0.69 b,w & 3.47 \(\pm\) 4.03 a,w \\ \(\Delta\)E in relation to CB & & & & \\ CB & 0.00 \(\pm\) 0.00 c,x & 0.00 \(\pm\) 0.00 c,x & 0.00 \(\pm\) 0.00 c,x & 0.00 \(\pm\) 0.00 b,x \\ FRB & 5.60 \(\pm\) 0.91 b,w & 0.97 \(\pm\) 0.73 b,x & 7.77 \(\pm\) 0.15 b,w & 1.91 \(\pm\) 5.01 a,x \\ FRB-AE & 13.30 \(\pm\) 0.77 a,w & 15.09 \(\pm\) 0.73 a,w & 14.14 \(\pm\) 0.21 a,w & 4.97 \(\pm\) 2.46 a,x \\ FRB-TAE & 14.01 \(\pm\) 0.85 a,w & 14.47 \(\pm\) 0.81 a,w & 13.47 \(\pm\) 0.12 a,w & 2.80 \(\pm\) 4.45 a,x \\ \hline \hline \end{tabular}  
*c: Different letters within the same row indicate significant differences between burger formulations (\(p<0.05\)). _w-z_. Different letters within the same column indicate significant differences between days of storage (\(p<0.05\)). CB: control burger; FRB: fat-replaced burger; FRB-AE: fat-replaced burger with artichoke extract; FRB-TAE: fat-replaced burger with treated artichoke extract.  
\end{table} 
Table 5: pH and color evolution (CIELab) of raw and cooked burgers. were also observed between beef burger formulations during the shelf-life study on days 0, 1, and 3. At the end of storage at 4 \({}^{\circ}\)C, less total color change (\(\Delta\)E) was found among the burgers with added artichoke compared to the control formulations. All beef burgers experienced an increase in L* during storage; however, this increase was more aggressive in CB and FRB. Similar results were reported for a* values, where a decrease was found throughout the days except in FRB; however, a more aggressive reduction was observed in the control burgers.