Digestive Comparison of Epoxidized versus Native Large Yellow Croaker Phospholipids In Vitro and In Vivo : Focus on Oxylipin and Free Fatty Acid Profiles

The digestibility of dietary lipids is crucial to their health effects. This study investigated the digestion of oxidized phospholipids (EpPL) and native phospholipids (PL) using integrated in vitro and in vivo models and targeted oxylipin and free fatty acid (FFA) profiles. The lipolysis degree for EpPL (28.45%) was lower compared to that of PL (43.90%) during in vitro digestion, which was attributed to structural alterations in EpPL. In vivo, the release window for epoxy fatty acids (EpFAs) from EpPL was shorter and more limited than the release of FFA from PL. Serum analysis confirmed the systemic absorption of EpPL-derived metabolites, increasing the levels of 9,10-DiHOME and 14,15-EpETE, and the ω-6/ω-3 ratio, indicating an acute influx of pro-inflammatory mediators upon EpPL digestion. These findings provide important evidence of the impact of lipid oxidation products on health risks and offer new insights for future research on the digestion and metabolism of oxidized lipids.