## 4 Conclusions  
The enrichment of virgin flaxseed oil with different concentrations of dodecyl gallate, hydroxytyrosol acetate, and gamma-tocopherol, does not appreciably modify either the lipolysis degree reached during in vitro digestion or its lipolysis pattern in comparison with nonenriched oil. These results show that the phenolic compounds involved in this study, under the in vitro digestion conditions tested, do not inhibit the activity of lipases, or in other words, do not react with them affecting the hydrolytic reactions. In contrast, and although no significant differences were observed, the digestates of the virgin flaxseed oil enriched in the aforementioned phenols showed, in general, a slightly smaller percentage of triglycerides, and a slightly higher percentage of glycerol than the digestate of the nonenriched sample. These results are also reflected in the bioaccessibility of the oil main components. In vitro digestion causes a small oxidation degree which clearly affects the linolenic structures whose concentrations diminish, forming hydroperoxides supporting conjugated \(Z\),\(E\) dienic systems, which are primary oxidation compounds, and also volatile, secondary oxidation compounds, which are well known oxidation markers. Enrichment with the different phenols in the levels tested in this study reduced both the oxidation degree reached during the digestion of virgin flaxseed oil and the bioaccessibility of oxidation compounds, but not totally. Dodecyl gallate showed the best antioxidant efficiency, followed by hydroxytyrosol acetate and gamma-tocopherol. In the case of enrichment with gamma-tocopherol, it was observed that its antioxidant efficiency is related with the gamma-tocopherol concentration through a logarithmic relation. The concentrations of some minor components of the virgin flaxseed oil, such as cycloartenol, 24-methylenedycloartenol, terpen, and sesquiterpenes, were not modified by in vitro digestion, showing an in vitro bioaccessibility near the unity. However, the in vitro bioaccessibility of the gamma-tocopherol contained in virgin flaxseed oil was very small, but increased in line with the enrichment of phenolic compounds. It has been shown that oxidation occurs during in vitro digestion, even in the presence of high concentrations of gamma-tocopherol which remain bioaccessible after digestion in the enriched samples in this compound. Finally, it should be the units by which the antioxidant efficiency was measured should be noted, since a lack of clarity in this respect could be the cause of the divergences among other studies regarding the antioxidant efficiency order. **Supplementary Materials:** The following are available online at [[http://www.mdpi.com/2076-3921/9/4/312/s1](http://www.mdpi.com/2076-3921/9/4/312/s1)]([http://www.mdpi.com/2076-3921/9/4/312/s1](http://www.mdpi.com/2076-3921/9/4/312/s1)), Table S1: Composition and pH values of the juices employed in the in vitro digestion model employed in this study; Table S2: Chemical shift assignments and multiplicities of the \({}^{1}\)H NMR signals in CDCl\({}_{3}\) of protons of glycerides; Table S3: Chemical shift assignments and multiplicities of the \({}^{1}\)H NMR signals in CDCl\({}_{3}\) of protons of acyl groups and fatty acids; Table S4: Chemical shift assignments and multiplicities of the \({}^{1}\)H NMR signals in CDCl\({}_{3}\) of protons of some oxidation compounds detected in the digestates and formed during the in vitro digestion; Table S5: Chemical shift assignments and multiplicities of the \({}^{1}\)H NMR signals in CDCl\({}_{3}\) of protons of cycloartenol and methylencyolaartenol, esters of cycloartenol and methylencyolaartenol, gamma-tocopherol,hydroxytrosol acetate and dodecyl gallate detected in the samples before and after in vitro digestion; Equations used for the quantification from \({}^{1}\)H NMR spectral data of several compounds present in the starting samples and/or in the lipid extract of the digestates; Figure S1.