## 3 Results and Discussion
### Lipid Oxidation  
In meat and meat products, TBARS and hexanal content are generally considered to be reliable indices for evaluating the extent of lipid oxidation and, thus, the development of oxidative \"off flavour\" (i.e., rancidity), which is recognised as a serious problem during the storage of meat products. However, TBARS testing has been the object of criticism because it is not specific enough to quantify lipid peroxidation products, as previously reported [1; 22]. In the present study, the results showed that dietary supplementation with VE or EcoE significantly affected the TBARS production (Table 3). Indeed, the two different dietary treatments, VE and EcoE, at both the tested concentrations significantly decreased TBARS content with respect to the basal diet, although with some differences. This beneficial effect disappeared over a storage time of 4 days (t4) in the EcoE 200 group and in the VE groups. In the Eco100 group, the beneficial effect disappeared at t2. The lower TBARS content in all the treated groups with respect to the control group, already perceivable at t0, could be considered the first positive outcome of dietary supplementation with VE or Se instead of their simple addition to meat as preservatives. The decrease in TBARS is particularly evident in the group treated with VE 200, where the values are more than halved compared with the control (about 45% compared with the \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{2}{c}{**Dietary Groups**} & \multicolumn{6}{c}{**TBARS (mg MDA/kg Product)**} \\ \cline{2-7}  & \multicolumn{2}{c}{**CTRL**} & **VE100** & **VE200** & **EcoE100** & **EcoE200** \\ \hline \multirow{4}{*}{Storage time} & t0 & 0.751 \({}^{\text{ax}}\)\(\pm\) 0.026 & 0.408 \({}^{\text{bx}}\)\(\pm\) 0.007 & 0.347 \({}^{\text{bx}}\)\(\pm\) 0.029 & 0.501 \({}^{\text{bx}}\)\(\pm\) 0.070 & 0.344 \({}^{\text{bx}}\)\(\pm\) 0.039 \\  & t1 & 0.773 \({}^{\text{ax}}\)\(\pm\) 0.010 & 0.477 \({}^{\text{bx}}\)\(\pm\) 0.155 & 0.376 \({}^{\text{bx}}\)\(\pm\) 0.092 & 0.479 \({}^{\text{bx}}\)\(\pm\) 0.024 & 0.522 \({}^{\text{bx}}\)\(\pm\) 0.114 \\  & t2 & 0.775\({}^{\text{ax}}\)\(\pm\) 0.016 & 0.431 \({}^{\text{bx}}\)\(\pm\) 0.036 & 0.335 \({}^{\text{bx}}\)\(\pm\) 0.046 & 1.091 \({}^{\text{cy}}\)\(\pm\) 0.130 & 0.515 \({}^{\text{bx}}\)\(\pm\) 0.039 \\  & t4 & 1.445 \({}^{\text{y}}\)\(\pm\) 0.023 & 1.312 \({}^{\text{y}}\)\(\pm\) 0.275 & 1.359 \({}^{\text{y}}\)\(\pm\) 0.062 & 1.273 \({}^{\text{y}}\)\(\pm\) 0.174 & 1.373 \({}^{\text{y}}\)\(\pm\) 0.127 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The effects of dietary supplementation with \(\alpha\)-tocopherol acetate (VE) or EconomicsET(EcoE) and storage time on the TBARS (mg MDA/kg product) of packaged rabbit hamburgers. control). Compared with raw meat, processed meat such as hamburgers is more susceptible to oxidative damage due to physical manipulation during the manufacturing process, involving the disruption of muscle structure and the exposure of muscle lipids to an oxidative environment. In this case in particular, dietary VE deposited into subcellular structures becomes an integral part of muscle and fat tissue, thus becoming very effective against lipid oxidation as previously reported [34]. In fact, [PERSON] et al. [5] recently reported that dietary supplementation with VE, at the same concentrations used in the present work, increased the content of this antioxidant in the same meat preparation (Table 2, \"Materials and Methods\" section). Hexanal, being a specific indicator of the oxidation of important long-chain unsaturated fatty acids, in particular \(\omega\)-6 PUFA, has been reported to be a valid and specific indicator of oxidative stability [35], and, thus, it could be used as a marker of lipid oxidative processes regarding hamburger shelf-life. In this study, however, the richness of \(\omega\)-6 fatty acids both in diets and in metals, highlighted in the previous study by [PERSON] et al. (2020), makes hexanal a good marker for studies relating to lipid oxidation.