Electroformation and characterization of soybean protein isolate hydrolysates-modified liposomes

This research aimed to elucidate the application and feasibility of the enhancement of liposome oxidative stability by the interaction of liposomes with soybean protein isolate hydrolysates (SPIHs) during liposome electroformation. It was observed that the degree of hydrolysis, percentage of low-molecular-weight distribution, and solubility of SPIHs after enzymatic hydrolysis increased with the extension of reaction time. The average fluorescence intensity (average gray level) was approximately 200 a.u. for each liposome, indicating a homogeneous distribution of SPIHs on the liposome surface. Moreover, it was found that the advanced structure of SPIHs incorporated with liposomes was altered appreciably. Both hydrophobic forces and hydrogen bonds exhibited an important role in the interaction between SPIHs and liposomes. In addition, morphology observation indicated that the liposomes were spherical and exhibited a more compact structure after coating with SPIHs. Subsequent flow cytometry analysis showed that the diameter and number of vesicles would increase due to vesicles rupturing or reorganizing after phospholipid oxidation during the electroformation of liposomes to produce SPIHs-liposomes. While the phospholipid oxidation level of the original liposomes was 42.13%, the phospholipid oxidation level of SPIHs-liposomes did not exceed 25%, indicating that the optimal balance between electroformation parameters and phospholipid oxidation level was obtained. These results may provide novel insight into the implications of SPIHs-modified liposomes as functional additives.