Regulated the aggregation of bile salts by β-Cyclodextrin and Tangeretin at the oil-water interface for inhibiting lipid digestion

Abstract

Our previous research has demonstrated that the changes in oil-water interface properties during dietary digestion have a significant impact on the digestion and absorption of lipids. In this study, these methods of interfacial tension, microscopic examination, isothermal titration calorimetry (ITC), molecular dynamics (MD) simulations, and free fatty acid (FFA) release were used to evaluate the effect and mechanism of assembly behavior of tangeretin (TAN) and β-cyclodextrin (β-CD) at the oil-water interface on the rate of lipid digestion. The results showed that the combination of β-CD and TAN at the oil-water interface made the interfacial tension first increase and then decrease with the increase of TAN: β-CD ratios (M: M, 1:1-20). The self-assembled structure formed by the interaction of TAN and β-CD can produce stronger interaction with bile salts, which makes bile salts flocculate at the oil-water interface. The FFAs release experiment showed that a TAN: β-CD molar ratio of 1:8 exerted the highest inhibitory (34.92%) effect on lipid digestion. Furthermore, the results from ITC and MD simulations confirmed that BS exhibited stronger binding affinity with the TAN/β-CD complex. These results suggested that the TAN/β-CD complex caused the bile salts to prematurely gather at the oil-water interface, thereby thickening the interfacial layer, hindering the displacement of bile salts and lipase between droplets, and ultimately impeding lipid digestion. This study emphasized the promising potential of the synergistic effect between cyclodextrin and flavoring molecules in inhibiting lipid digestion, proposing a novel avenue for the development of reduced-fat foods with enhanced health benefits.