## 3 Results and Discussion
### Sensorial Analysis  
Extracts addition could have a negative effect on the appearance, aroma, and taste, especially when their concentrations are high [49]. To determine the influence of lees addition on sensorial characteristics, QDA was carried out in raw and cooked burgers at the beginning of storage (day 0). In raw samples, appearance and odor attributes were evaluated (Figure 4A). The characteristic purple red color decreased in samples with lees. The higher lees concentration, the lower color scores (0 = brown, 10 = bright red). As it was observed in instrumental color, a* values were lower in samples with lees (Table 2). Regarding odor attributes, samples with wine lees showed new particular odors that attenuated the typical meaty odor. These new attributes were assessed as \"wine\" in samples with \"verdejo\" lees (Lva, Lvb) and \"bakery\" and \"raisins\" for samples with \"palomino\" lees (Lpa, Lpb). The color alteration and typical sensorial changes were also observed by other authors after adding grape seed and peel extracts in a chicken meat product [14].  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Principal Component** & **Compounds** & **Loadings** \\ \hline PC 1 & Butyl decanoate & 0.981 \\  & Propyl decanoate & 0.967 \\  & 3-Methylbutyl decanoate & 0.967 \\  & Octanoic acid & 0.964 \\  & Phenylethyl alcohol & 0.956 \\  & 3-Methylbutyl octanoate & 0.955 \\  & Methyl dodecanoate & 0.949 \\  & Methyl decanoate & 0.945 \\ \hline PC 2 & Benzaldehyde & 0.956 \\  & 1-Hexanol & 0.942 \\  & 1-Nonanol & 0.919 \\  & Ethyl-hexanoate & 0.915 \\  & Pentanoic acid & 0.909 \\  & (E)-2-octen-1-ol & 0.908 \\  & 1-Octen-3-ol & 0.906 \\  & Hexyl hexanoate & 0.904 \\  & Hexanoic acid & 0.899 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Result of principal component analysis applied to volatile data obtained from deer burgers at 0 and 12 days of chilled storage. Volatile compounds more correlated with the two first Principal Component and their loading.  
Regarding cooked burgers (Figure 4B,C), control samples were characterized by a higher rose color and \"roasted meat\" odor. However, in burgers with lees, the new taste attributes also appeared--\"raisins\" (Lpa and Lpb) and \"wine\" (Lva and Lvb), being their intensities proportional to the lees concentration. These new attributes were considered as pleasant at low intensities and could be associated with the higher amounts of esters, acids, and benzene compounds detected in the  
Figure 4: Quantitative descriptive analysis of raw and cooked venison burgers. Symbols: --- C; --- Lva; --- Lvb; --- Lpa; --- Lpb. C: sodium ascorbate control; Lva: 2.5% “verdejo” lees; Lvb: 5% “verdejo” lees; Lpa: 2.5% “palomino” lees; Lpb: 5% “palomino” lees. (**A**) Raw burgers: Appearance and odor attributes; (**B**) Cooked burgers: Appearance and odor attributes; (**C**) Cooked burgers: Taste and texture attributes.  
Figure 3: Distribution of deer burgers during chilled storage in the space defined by the first two Principal Components (PC1 and PC2). The selected variable was the volatile composition analyzed by SPME-GC-MS. C: sodium ascorbate control; Lva: 2.5% “verdejo” lees; Lvb: 5% “verdejo” lees; Lpa: 2.5% “palomino” lees; Lpb: 5% “palomino” lees.  
volatile profile of burgers with lees. They were positively appreciated by the panelists. The use of wood extract as natural antioxidants modified slightly and pleasantly the typical aroma of raw pork parties [16]. Acid taste appeared only in samples with lees. Moreover, lees addition offered more juiciness and tenderness to deer burgers that increased with the lees concentration.