Complex phospholipid liposomes co-encapsulated of proanthocyanidins and α-tocopherol: Stability, antioxidant activity and in vitro digestion simulation

In this study, proanthocyanidins (PA) and α-tocopherol (α-TOC) were co-encapsulated in complex phospholipid liposomes, to improve the chemical stability of PA and α-TOC and the antioxidant properties of the liposomes. The results showed that the liposome had a spherical microstructure with no adhesions. The encapsulation efficiency of PA and α-TOC reached 78.02% ± 2.02% and 81.67% ± 1.25%, respectively, and interacted with the phospholipid bilayer through hydrogen bonding. The addition of hydrogenated soybean lecithin (HSL) conferred better stability to the liposomes and improved their protection against PA and α-TOC. The retention of PA and α-TOC in liposomes remained above 60% after 30 d of storage at 4 °C. Due to the synergistic antioxidant effect of PA and α-TOC, the DPPH radical scavenging activity of PA-TOC-CPL reached 87.52%, which was significantly higher than that of single-embedded PA and α-TOC liposomes. The release of PA and α-TOC from PA-TOC-CPL during simulated digestion was low and the release pattern could be described by the Ritger-Peppas model. This serves as a reference to guide the utilization of HSL and the development of liposomal products with higher antioxidant properties.