Interaction of DPPC liposomes with cholesterol and food protein during in vitro digestion using Dynamic Light Scattering and FTIR spectroscopy analysis

The influence of cholesterol (CHO), bovine serum albumin (BSA) and lactoferrin (LF), on the phase transition temperature (Tm) and structure of DPPC liposomes during in vitro digestion was investigated using Dynamic Laser Scattering (DLS) and Fourier Transform Infrared Spectroscopy technologies (FTIR). CHO enhanced bilayers thickness and acyl chain order, especially in DPPC:CHO of 6:1, with the average size increase to 1.77 +/- 0.20 mu m and broaden of phase transition (Tm 45.8 degrees C). Protein critically impacted on the liposomal structure through formation of hydrogen bonds between in DPPC and protein. Liposomal size and Tm were significantly changed after simulated gastric digestion, whereas the pancreatic incubation can broaden transition phase and weaken functional groups of liposomes. Our data provided a better understanding on structure changes of CHOcontaining membrane and protein addition by revealing Tm and chemical bonds details, and added to current knowledge for evaluating the different component on liposomal digestibility in food area.