## 2 Results and Discussion
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Biscuits Sample**} & **Rutin** & **TPC** & **Antioxidant Capacity** \\  & [\(\mu\)g/g of DW] & **[mg GAE/g of DW]** & **[\(\mu\)mol Trolox/g DW]** \\ \cline{3-4}  & & & **DPPH** & **OxHLIA** \\ \hline CB & 1.78 \(\pm\) 1.78 \({}^{\text{e}}\) & 0.90 \(\pm\) 0.03 \({}^{\text{e}}\) & 2.65 \(\pm\) 0.01 \({}^{\text{c}}\) & 10.67 \(\pm\) 0.06 \({}^{\text{d}}\) \\ RBB & 28.51 \(\pm\) 3.84 \({}^{\text{d}}\) & 2.22 \(\pm\) 0.09 \({}^{\text{d}}\) & 2.84 \(\pm\) 0.04 \({}^{\text{b}}\) & 11.39 \(\pm\) 0.02 \({}^{\text{c}}\) \\ RBB-L & 37.73 \(\pm\) 6.59 \({}^{\text{c}}\) & 4.77 \(\pm\) 0.35 \({}^{\text{c}}\) & 2.88 \(\pm\) 0.04 \({}^{\text{b}}\) & 11.34 \(\pm\) 0.03 \({}^{\text{c}}\) \\ RBB-M & 115.13 \(\pm\) 55.74 \({}^{\text{b}}\) & 10.35 \(\pm\) 0.38 \({}^{\text{b}}\) & 2.98 \(\pm\) 0.05 \({}^{\text{b}}\) & 11.82 \(\pm\) 0.01 \({}^{\text{bc}}\) \\ RBB-H & 273.72 \(\pm\) 1.08 \({}^{\text{a}}\) & 22.39 \(\pm\) 0.08 \({}^{\text{a}}\) & 3.22 \(\pm\) 0.09 \({}^{\text{a}}\) & 12.34 \(\pm\) 0.05 \({}^{\text{a}}\) \\ \hline \hline \end{tabular} Abbreviations: CB—control biscuits made of rye flour, RBB—rye-buckwheat biscuits made of rye and light buckwheat flour (70:30, w/w), RBB—rye-buckwheat biscuits made of rye and light buckwheat flour with low rutin addition (5 mg rutin/100 g of product), RBB–rye-buckwheat biscuits made of rye and light buckwheat flour with medium rutin addition (25 mg rutin/100 g of product), RBB-H—rye-buckwheat biscuits made of rye and light buckwheat and light buckwheat flour with high rutin addition (50 mg rutin/100 g of product). DW: dry weight, GAE: Gallic acid equivalents. Data are expressed as means \(\pm\) SD, each measurement was repeated in triplicate. Values in each column with different small superscript letters are significantly different (\(\rho<0.05\)).  
\end{table} 
Table 1: Rutin and Total Phenolic Compounds (TPC) contents and antioxidant capacities of rye-buckwheat biscuits enriched with rutin as determined by DPPH and OxHLIA methods. the degradation of flavonoids. Consequently, OxHLIA results ranged from 10.67 (control) and 11.39 (30% buckwheat addition) to 12.34 umol Trolox/g DW. The OxHLIA method is based in principle on the inhibition of free radical-induced membrane damage in erythrocytes by antioxidants [21]. The incorporation of 30% of buckwheat flour significantly increased the antioxidant potential of rye-buckwheat biscuits, almost 7% in RBB. Then, no significant change was observed after low and medium rutin addition (RBB-L and RBB-M). Only the addition of a high amount of rutin to biscuits increased their antioxidant potential, by 15 and 8% when compared RBB-H to C and RBB, respectively. The antioxidant potential of RBB-H samples was on the same level as orange and strawberry juices measured using AAPH-induced cell hemolysis method by [PERSON] et al. [22]. High correlation coefficients between rutin vs. TPC contents, rutin vs. DPPH and rutin vs. OxHLIA were calculated (r = 0.997; 0.950; 0.917). Moreover, the strong correlation was noticed between TPC content and antioxidant activity (r = 0.953; 0.916 for DPPH and OxHLIA, respectively). This is in accordance with [PERSON] et al. [23], who reported that rutin is \"a powerful free radical inhibitor or scavenger\" using DPPH assay. Our results also pointed out that there is a strong correlation between DPPH and OxHLIA assays (r = 0.988).