## 3 Results and Discussion
### Physicochemical Properties of Baked Meat, Hybrid, and Plant Burgers
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Recipe Variant**} & \multirow{2}{*}{**Measurement**} & \multicolumn{5}{c}{**Sample Type**} \\ \cline{3-6}  & & **M100\_P0** & **M75\_P25** & **M50\_P50** & **M25\_P75** & **M0\_P100** \\ \hline \multicolumn{6}{c}{**L* [–]**} \\ \hline I & Surface & 53.1 \(\pm\) 2.0 cA & 51.2 \(\pm\) 2.0 bCA & 48.9 \(\pm\) 2.4 abc & 47.0 \(\pm\) 1.5 aB & 44.1 \(\pm\) 1.7 aA \\  & Cross-section & 62.2 \(\pm\) 1.9 cA & 58.6 \(\pm\) 2.3 bc & 56.7 \(\pm\) 1.0 aB & 53.0 \(\pm\) 2.4 aA & 51.8 \(\pm\) 2.3 aA \\ II & Surface & 53.1 \(\pm\) 2.0 cA & 51.2 \(\pm\) 1.0 bCA & 47.4 \(\pm\) 1.8 aB & 45.2 \(\pm\) 1.2 aA & 45.8 \(\pm\) 0.6 aA \\  & Cross-section & 62.2 \(\pm\) 1.9 dA & 59.4 \(\pm\) 1.3 cdA & 55.6 \(\pm\) 1.0 bCA & 54.4 \(\pm\) 1.3 aB & 50.4 \(\pm\) 0.9 aA \\ \hline \multicolumn{6}{c}{**a* [–]**} \\ \hline I & Surface & 14.2 \(\pm\) 0.6 bA & 10.1 \(\pm\) 1.6 aB & 9.1 \(\pm\) 1.9 aA & 9.1 \(\pm\) 1.8 aA & 8.8 \(\pm\) 2.5 aA \\  & Cross-section & 14.7 \(\pm\) 0.8 aA & 10.2 \(\pm\) 2.1 bA & 8.0 \(\pm\) 1.2 aB & 5.8 \(\pm\) 2.1 aA & 6.6 \(\pm\) 1.4 bA \\ II & Surface & 14.2 \(\pm\) 0.6 bA & 11.6 \(\pm\) 0.9 aA & 11.6 \(\pm\) 0.4 aA & 12.5 \(\pm\) 1.2 aB & 13.0 \(\pm\) 0.7 aB \\  & Cross-section & 14.7 \(\pm\) 0.8 bA & 10.0 \(\pm\) 1.2 aA & 10.4 \(\pm\) 0.5 aA & 9.4 \(\pm\) 0.9 aA & 9.6 \(\pm\) 0.4 aA \\ \hline \multicolumn{6}{c}{**b* [–]**} \\ \hline I & Surface & 5.1 \(\pm\) 0.7 aA & 8.0 \(\pm\) 0.4 aB & 10.6 \(\pm\) 1.4 bCA & 12.7 \(\pm\) 1.8 cA & 10.9 \(\pm\) 0.9 bCA \\  & Cross-section & 4.2 \(\pm\) 0.3 aA & 9.5 \(\pm\) 1.1 bA & 11.2 \(\pm\) 1.3 bCA & 14.0 \(\pm\) 1.5 cdA & 15.0 \(\pm\) 1.8 aA \\ II & Surface & 5.1 \(\pm\) 0.7 aA & 12.7 \(\pm\) 2.0 bA & 14.3 \(\pm\) 2.3 bA & 14.7 \(\pm\) 2.2 bA & 16.8 \(\pm\) 3.0 bB \\  & Cross-section & 4.2 \(\pm\) 0.3 aA & 11.9 \(\pm\) 3.2 bA & 15.9 \(\pm\) 0.9 bCA & 18.7 \(\pm\) 1.8 cB & 19.6 \(\pm\) 1.1 cA \\ \hline \multicolumn{6}{c}{**\(\Delta\)E1 [–]**} \\ \hline I & Surface & - & 6.1 \(\pm\) 1.6 aA & 9.0 \(\pm\) 1.4 abA & 11.1 \(\pm\) 1.3 bCA & 12.2 \(\pm\) 0.4 cA \\  & Cross-section & - & 8.0 \(\pm\) 2.8 aA & 11.3 \(\pm\) 2.1 aA & 16.3 \(\pm\) 0.9 bA & 17.3 \(\pm\) 0.9 bA \\ II & Surface & - & 8.3 \(\pm\) 2.2 aA & 11.1 \(\pm\) 1.4 aB & 12.6 \(\pm\) 1.6 aB & 14.0 \(\pm\) 2.4 bA \\  & Cross-section & - & 11.6 \(\pm\) 1.8 aA & 13.6 \(\pm\) 1.5 aA & 17.5 \(\pm\) 1.1 bA & 20.2 \(\pm\) 0.9 bA \\ \hline \hline \end{tabular}  
* For the denomination of hybrid burger samples, see Table 1. \(\Delta\)E\({}_{\text{I}}\)—total color difference in burgers compared to the meat sample (M100\_P0). Different lowercase letters between means values \(\pm\) standard deviations in the row indicate significant differences (grouping variable: sample type), \(p\leq 0.05\). Different uppercase letters between means values \(\pm\) standard deviations in the column for a given measurement indicate significant differences (grouping variable: recipe variant), \(p\leq 0.05\).  
\end{table} 
Table 5: Surface and cross-section color parameters of baked meat, hybrid, and plant burgers. As expected, all tested burgers were characterized by a lighter color (higher values of the L* color parameter) in the cross-section than on their surface, which resulted from the direct impact of various external factors (e.g., oxygen or heat) on the surface of the samples. Overall, the burgers were much darker as more of the multi-ingredient plant mixture was used. However, the observed differences were not due to the recipe variant (\(p>0.05\)). The lighter color of the meat was presumably caused by the thermal denaturation of myofibrillar, sarcoplasmic, and connective tissue proteins [67; 68]. On the other hand, the darker color of plant parts in burgers could result from a relatively high carbohydrate content, which favors Maillard reactions [69; 70]. Likewise, reducing the meat content in burgers resulted in a decrease in the a* color parameter, except for the surface color of the burgers, based on the recipe variant II.