Modulating digestion behavior, antioxidant activity, and cytotoxicity of rice bran oil bodies through interface...

Rice bran oil bodies (RBOBs) are natural oil-in-water emulsions stabilized by phospholipid-oleosin membranes. This study investigated interfacial engineering with tannic acid on RBOB in vitro digestion. Initial RBOB particle sizes (0.95-2.44 μm) reduced to nanoscale (291-847 nm) after oral digestion. The gastric phase induced aggregation due to diminished electrostatic repulsion, and the intestinal phase formed self-assembled mixed micelles. Tannic acid binding, especially covalently, decreased free fatty acid release, protein hydrolysis, and free amino acid release by 30.52%, 13.75%, and 15.07%, respectively. Lipidomics revealed a transition from triacylglycerols to diacylglycerols, showing free fatty acid release below 25% due to interfacial phospholipid enzymatic resistance. Digestates retained high nutritional quality, with essential amino acids comprising 52.54-60.27%. RBOBs demonstrated excellent safety, exhibiting over 99% cell viability at 0.2-5.0 mg/mL and tannic acid-enhanced antioxidant activity. These findings emphasize interfacial engineering to create OB-based low-fat foods that regulate lipid digestion and improve nutrition.