An in vitro intestinal model was used to evaluate the impact of banana condensed tannins (BCT) on the digestion of lipids (fat and cholesterol). BCT significantly suppressed the digestion of fat and cholesterol by interacting with digestive juice components. The interactions of BCT with a digestive juice mixture and its components (including bile acid, lipase, cholesterol esterase, CaCl2, NaCl, and cholesterol) were analyzed using turbidity, isothermal titration calorimetry, particle size distribution, zeta potential, and molecular docking analyses. The results showed that BCT reduced the digestion of lipids mainly via interaction with lipase, cholesterol esterase, bile acid, and cholesterol. Electrostatic CT-calcium ion complexes might reduce the extent of lipid digestion by decreasing the surface area of the lipid droplets exposed to the enzymes. This research provides valuable insights into the molecular mechanisms of the interaction of BCT with digestive juice components related to lipid digestion that may affect the rate and extent of lipid digestion.
Keywords: condensed tannins; digestive juice components; flocculation; isothermal titration calorimetry; lipid digestion; turbidity.