## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{3}{*}{**Food Sample**} & \multicolumn{3}{c}{**Before Digestion**} & \multicolumn{3}{c}{**After Digestion**} & \multicolumn{3}{c}{**Bioavailability of**} & \multirow{3}{*}{**P1**} & \multirow{3}{*}{**P2**} \\  & \begin{tabular}{c} **Total** \\ **Antivoal** \\ **Capacity** \\ **(mmol Fe\({}^{12}\)/L)** \\ \end{tabular} & \begin{tabular}{c} **Total** \\ **Conteal** \\ **(mgmgGAE/L)** \\ \end{tabular} & \begin{tabular}{c} **Total** \\ **Antivoal** \\ **Capacity** \\ **(mmol Fe\({}^{12}\)/L)** \\ \end{tabular} & \begin{tabular}{c} **Bioavailability of** \\ **Total** **Antivoalant** \\ **(mgmgGAE/L)** \\ \end{tabular} & \begin{tabular}{c} **Bioavailability of** \\ **Total** **Antivoalant** \\ **Capacity** **(BavI \%)** \\ \end{tabular} & \begin{tabular}{c} **Bioavailability of** \\ **Total** **Phenonic** \\ **Content** **(BavI \%)** \\ \end{tabular} & \
\begin{tabular}{c} **P1** \\ **P2** \\ **Content** **(BavI \%)** \\ \end{tabular} &
\begin{tabular}{c} **P2** \\ **Content** **(BavI \%)** \\ \end{tabular} \\ \hline \multicolumn{7}{c}{**Plant By-products**} \\ \hline Orange peel & 1.24 \(\pm\) 0.24 d & 64.35 \(\pm\) 25.31 d & 0.06 \(\pm\) 0.01 a & 13.28 \(\pm\) 10.84 a & 4.84 & 20.64 & * & **...** \\ Pomegranate peel & 1.25 \(\pm\) 0.09 d & 42.31 \(\pm\) 4.77 c & 0.08 \(\pm\) 0.02 a & 20.95 \(\pm\) 13.93 a & 6.40 & 49.52 & * & **...** \\ Pomeac & 0.37 \(\pm\) 0.05 bc & 20.27 \(\pm\) 4.86 b & 0.11 \(\pm\) 0.10 a & 9.86 \(\pm\) 8.39 a & 29.73 & 48.64 & * & * & * \\ \hline \multicolumn{7}{c}{**Hethes**} \\ \hline Basil & 0.42 \(\pm\) 0.03 c & 58.15 \(\pm\) 39.34 d & 0.09 \(\pm\) 0.03 a & 11.29 \(\pm\) 7.29 a & 21.43 & 19.42 & * & **...** \\ St. John’s Wort & 0.32 \(\pm\) 0.08 b & 17.38 \(\pm\) 8.59 b & 0.07 \(\pm\) 0.01 a & 9.23 \(\pm\) 8.47 a & 21.88 & 53.11 & *** & NS \\ \hline \multicolumn{7}{c}{Data are expressed as mean \(\pm\) SD. Different letters in the same group (antioxidant capacity or phenolic content) presented significant differences (\(p<\) 0.05) between samples. BavI: Bioavailability Index. P1: Total antioxidant capacity: sample correlations between before and after in vitro digestion. P2: Total phenolic content: correlations between samples before and after in vitro digestion. Significance level *** \(p<\) 0.001, *** \(p<\) 0.01, * \(p<\) 0.05 NS: non-significant (\(p>\) 0.05).} \\ \end{tabular}
\end{table} 
Table 9: Total antioxidant capacity and total phenolic content of selected fortified olive oils before and after in vitro digestion and their predicted bioavailability indices. oil with compounds rich in antioxidants and polyphenols. Nevertheless, it depends on the herb and/or plant by-product used in the fortification process to determine which method can be assumed as suitable for antioxidant and phenolic content enhancement. Our study results showed that refined olive oil fortified with pink savory, sage, basil, St. John's wort, pomegranate, lemon, and orange peel extract presented the highest total antioxidant capacity and polyphenic content among all three methods, comparable to the total antioxidant capacity and polyphenic content of virgin and extra virgin olive oil studied. Yet, in each enrichment method used, there were observed differences in the antioxidant and phenolic content of the fortified refined olive oil as presented in detail below. Conventional maceration has been mainly used in the food industry, as it is a technologically simple low-cost method [36]. Olive oil by-products have been examined as a protentional way of fortifying olive oil, using conventional maceration methods. Olive leaves have been used for the fortification of olive oil, using conventional maceration in different concentrations between 1 and 10% for 7 days, and the fortified final products presented a higher percentage of phenolic components compared to the unfortified samples [37].