Differential digestive fate of palm oil and palm-based diacylglycerol oil: linking physicochemical properties, oxidative stability and pancreatic lipase specificity.

The physicochemical properties of structured lipids play a decisive role in their digestive behavior and health relevance. This study systematically compared palm oil (PO) and palm oil-based diacylglycerol oil (PO-DAG) by integrating structure-property-digestion relationships with pancreatic lipase specificity. Compared to PO, PO-DAG exhibited a higher melting point and better oxidative stability during ambient storage, and was also less prone to the accumulation of oxidative products under heating and frying conditions. Using an in vitro gastrointestinal digestion model, we found that PO-DAG was digested more slowly than PO during the intestinal phase. The stage-specific distributions of TAG, DAG, MAG, and FFA indicated that lipolysis showed clear region-dependent patterns along the digestive tract. Enzyme kinetics and molecular docking revealed that pancreatic lipase preferentially binds and hydrolyzes sn-1,2 DAG over sn-1,3 DAG, providing a mechanistic basis for the unique digestive fate of PO-DAG. Collectively, these findings clarify why PO-DAG does not simply digest faster than conventional palm oil and advance our understanding of structured lipid digestion.