Conformational changes of proteins and oil molecules in fish oil/water interfaces of fish oil-in-water emulsions stabilized by bovine serum albumin

This study investigated the conformational changes in proteins and oil molecules at fish oil/water interfaces. Results of FT-IR indicate that α-helical content of bovine serum albumin decreased (from 46.1% to 28.4%), and β-sheet and random coil contents increased (from 15.5% and 13.5% to 18.9% and 28.1%, respectively) after protein adsorption at the fish oil/water interface. Fluorescence emission maximum of emulsions showed a blue shift compared to native proteins. FT-IR spectra of oil molecules showed broadenings in CH stretching vibration peaks of CH3 and CH2 groups of the fish oil. These results combined with structural information of BSA in the protein database led to the following hypothesis: binding occurs between proteins and lipid molecules in the oil-water interface. This study provides insight into the conformational changes of proteins and oil molecules in fish oil/water interfaces and broadens the fundamental understanding of the possible stability mechanisms of emulsions stabilized by proteins.