# Two-Step Enzymatic Synthesis of Structured Triacylglycerglycerols from ARASCO+
## 3 Results and Discussion
### STAG Synthesis and Purification  
The regiospecific distribution of FA in the resulting STAG with the three lipases tested is shown in Table 2, together with the FA profiles of the substrates used in the synthesis: the ethanolysis products of coconut oil containing FAEEs (substrate 1) and the ethanolysis products of the ARA-rich fraction purified from ARASCO containing _sn_-2 MAGs (substrate 2). STAGs were collected between fractions 24 and 40 of the silica gel-silver nitrate gravimetric chromatographic column described in Section 2.4, and the purity was checked by TLC. The alcoholysis products of coconut oil were rich in lauric acid (LaA, 12:0), followed by myristic acid (44.2 and 17.1% of total FA, respectively). The alcoholysis products of the ARA-rich fraction contained mainly ARA (78.6% of total FA). STAG synthesized with _T. lanuginos_ lipase showed the highest proportion of MMM-type TAGs, where M is CA, CpA or LaA located at the three available positions of the glycerol backbone, probably due to acyl migration that shifted the FA located at the _sn_-2 position in MAGs to one of the outer positions (_sn_-1,3) to be further released by the lipase and replaced by a MCFA. STAGs with relatively high content of MMM-TAGs are interesting from a nutritional point of view because MCFAs are rapidly delivered to the liver after intestinal digestion due to their smaller molecular size compared to LCFAs and are used as a fast energy source by \(\beta\)-oxidation [37]. STAGs produced by _R. oryaze_ lipase  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & & & & & & & & & & & \\ \hline \multicolumn{1}{c}{**Fatty Acids**} & & & & & & & & & & \\ \hline \multicolumn{1}{c}{**8.0**} & **10.0** & **12.0** & **14.0** & **16.0** & **18.0** & **18.1n-9** & **18.2n-6** & **18.3n-6** & **20.0 fa-6** \\ \hline \multicolumn{1}{c}{**SUBSTRATE 1**} & 8.6 & 6.1 & 44.2 & 17.1 & 9.2 & 2.9 & 9.2 & 2.7 & ND & ND \\ \hline \multicolumn{1}{c}{**SUBSTRATE 2**} & ND & ND & ND & ND & 5.1 & 2.9 & 3.6 & 4.6 & 5.1 & 78.6 \\ \hline \multicolumn{1}{c}{**STAG using**} & & & & & & & & & & \\ \multicolumn{1}{c}{_R. ergaze_ lipase} & & & & & & & & & & \\ \hline \multicolumn{1}{c}{**Whole STAG**} & \( \begin{array}{c}0.18\pm 0.04\\ \ast\\ \end{array} \) & \( \begin{array}{c}14.2\pm 0.31\\ \ast\\ \end{array} \) & \( \begin{array}{c}34.8\pm 1.0\\ \ast\\ \end{array} \) & \( \begin{array}{c}14.8\pm 0.9\\ \ast\\ \end{array} \) & \( \begin{array}{c}9.53\pm 0.80\\ \ast\\ \end{array} \) & \( \begin{array}{c}2.87\pm 0.47\\ \ast\\ \end{array} \) & \( \begin{array}{c}14.6\pm 1.3\\ \ast\\ \end{array} \) & \( \begin{array}{c}3.20\pm 0.30\\ \ast\\ \end{array} \) & \( \begin{array}{c}1.00\pm 0.26\\ \ast\\ \end{array} \) & \( \begin{array}{c}17.6\pm 1.0\\ \ast\\ \end{array} \) \\ \hline \multicolumn{1}{c}{**sn-2**} & \( \begin{array}{c}0.87\pm 0.15\\ \ast\\ \end{array} \) & \( \begin{array}{c}1.83\pm 0.40\\ \ast\\ \end{array} \) & \( \begin{array}{c}36.5\pm 0.9\\ \ast\\ \end{array} \) & \( \begin{array}{c}5.20\pm 0.40\\ \ast\\ \end{array} \) & \( \begin{array}{c}1.60\pm 0.50\\ \ast\\ \end{array} \) & \( \begin{array}{c}1.9\pm 0.04\\ \ast\\ \end{array} \) & \( \begin{array}{c}9.30\pm 0.56\\ \ast\\ \end{array} \) & \( \begin{array}{c}6.87\pm 0.67\\ \ast\\ \end{array} \) & \( \begin{array}{c}2.83\pm 0.47\\ \ast\\ \end{array} \) & \( \begin{array}{c}34.8\pm 1.0\\ \ast\\ \end{array} \) \\ \hline \multicolumn{1}{c}{**sn-1**-3**} & ND & \( \begin{array}{c}1.21\pm 0.39\\ \ast\\ \end{array} \) & \( \begin{array}{c}33.9\pm 1.1\\ \ast\\ \end{array} \) & \( \begin{array}{c}19.7\pm 1.1\\ \ast\\ \end{array} \) & \( \begin{array}{c}13.5\pm 1.0\\ \ast\\ \end{array} \) & \( \begin{array}{c}4.21\pm 0.73\\ \ast\\ \end{array} \) & \( \begin{array}{c}17.3\pm 2.2\\ \ast\\ \end{array} \) & \( \begin{array}{c}17.3\pm 2.2\\ \ast\\ \end{array} \) & \( \begin{array}{c}1.37\pm 0.78\\ \ast\\ \end{array} \) & \( \begin{array}{c}0.12\pm 0.10\\ \ast\\ \end{array} \) & \( \begin{array}{c}9.07\pm 1.05\\ \ast\\ \end{array}