Structure of Inclusion Complexes of Cyclodextrins with Triglyceride at Vegetable Oil/Water Interface

The interfacial tension of vegetable oil (soybean oil or coconut oil)/ water interface decreased with the increase of cyclodextrin (CD) concentration. The interfacial excess and interfacial area were calculated from the Gibbs’ adsorption equation. The average number of CD molecules including a fatty acid residue of soybean oil at the interface was estimated at 2.4 for each of α‐CD and β‐CD. The average number of CD molecules complexed with a fatty acid residue of coconut oil was 1.8 for α‐CD and 1.7 for β‐CD. These results suggested that the CD molecules formed the inclusion complex with the triglyceride according to the chain length of fatty acid residue at the interface.