Negative correlation between oil lipolysis and its LC-PUFA content in simulated digestion

Abstract

<p>The growing awareness of the pro-oxidant conditions of the gastrointestinal tract promotes attention to the fate of n-3 PUFAs after ingestion. These investigations primarily rely on <em>in vitro</em> models, with INFOGEST 2.0 being the most commonly applied. However, scarce attention is currently paid to the hydrolysis degree of the oils. In the present short communication, lipid digesta of DHA-rich oils, obtained after <em>in vitro</em> digestion, were analyzed with NMR spectroscopy. Rapeseed oil was used as positive control. Results showed that the DHA content of the oil negatively affected lipolysis, with an observed negative non-linear relationship between lipolysis extent and the long chain n-3/n-6 fatty acid ratio of the oil. ¹³C NMR revealed a clear negative relationship between lipolysis and relative amount of 22:6n-3 in the <em>sn</em>-1,3 position. This intrinsic obstacle should be taken into account during the <em>in vitro</em> research on behavior of n-3-rich oils in the gastrointestinal tract.</p>