## 3 Results and Discussion
### Lipid Oxidation of Chicken Meatballs
Despite the fact that, in the present study, more than twice as many polyphenic compounds were extracted from the ethanolic extract of buckwheat hulls as from the water extract (Table 1), the differences in antioxidant activity in the finished product (represented by TBARS values) were not significant (\(p<0.05\)). Studies in the literature report that the antioxidant activities of buckwheat hull extracts may be influenced not only by the flavonoids present but also by other compounds that may not have been extracted by the solvents used, as well as by interactions between the individual compounds [27]. It is noteworthy that in all variants of chicken meatballs the levels of MDA after 14 days of storage were lower than the limit reported by [PERSON] et al. [18], according to which meat products can be considered well-preserved in regard to oxidative changes, of less than 3 mg MDA/kg product. The oxidative stability of lipids extracted from chicken meatballs can also be characterised by the induction time determined on the basis of the PDSC technique, which makes it possible to study the stability of fats under elevated temperature conditions, in this case 120 \({}^{\circ}\)C, i.e., conditions close to the practical heat treatment of meat. The lower the induction time, the less stable the fat is, indicating the lower antioxidant activity of the extract. Fat extracted from chicken meatballs made with buckwheat hull extracts was characterised by a longer induction time than the fat extracted from the Control. For the fat extracted from the EE treatment, these differences were significant (\(p<0.05\)) for each of the analysed times. In contrast, for fat with WE, the significance of the differences was only marked after 1 and 7 days of storage, confirming the higher antioxidant potential of the ethanolic \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{4}{c}{**TBARS (mg MDA/kg)**} & \multicolumn{4}{c}{**Induction Time (min)**} \\ \cline{2-7}  & **1 1 ** & **7 & **14** & **1** & **7** & **14** \\ \hline Control & 0.65 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.05 & 0.85 \({}^{\mathrm{b}\,\mathrm{y}}\)\(\pm\) 0.08 & 0.88 \({}^{\mathrm{b}\,\mathrm{y}}\)\(\pm\) 0.05 & 12.22 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.34 & 11.43 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.52 & 11.22 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.72 \\ WE & 0.55 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.10 & 0.68 \({}^{\mathrm{a}\,\mathrm{b}\,\mathrm{y}}\)\(\pm\) 0.12 & 0.64 \({}^{\mathrm{a}\,\mathrm{y}}\)\(\pm\) 0.09 & 13.23 \({}^{\mathrm{b}\,\mathrm{x}}\)\(\pm\) 0.30 & 12.98 \({}^{\mathrm{b}\,\mathrm{x}}\)\(\pm\) 0.27 & 12.43 \({}^{\mathrm{a}\,\mathrm{b}\,\mathrm{x}}\)\(\pm\) 0.53 \\ EE & 0.56 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.07 & 0.55 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.10 & 0.56 \({}^{\mathrm{a}\,\mathrm{x}}\)\(\pm\) 0.06 & 13.61 \({}^{\mathrm{b}\,\mathrm{x}}\)\(\pm\) 0.43 & 13.49 \({}^{\mathrm{b}\,\mathrm{x}}\)\(\pm\) 0.47 & 12.74 \({}^{\mathrm{b}\,\mathrm{x}}\)\(\pm\) 0.29 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Evolution of TBARS values and induction times of chicken meatballs during refrigerated storage. extract. A reduction in induction time was observed during storage, but these differences were not significant (\(p>0.05\)), regardless of the meatball treatment. The results of the PDSC measurements for the oxidative stability of the fat extracted from the chicken meatballs are consistent with the results of the TBARS index determinations. The lower TBARS index values corresponded to longer induction times. According to us, this demonstrates the effective inhibition of lipid oxidation processes by buckwheat hull extracts.