Physicochemical properties, stability, and oxidation kinetics of Rosa roxburghii Tratt seed oil/β-carotene proliposomes modified with sodium alginate and chitosan bilayers

ObjectivesTo enhance the stability of proliposomes co-encapsulating Rosa roxburghii Tratt seed oil (RSO) and β-carotene (βC), sodium alginate (SA) and chitosan (CS) were utilized for bilayer surface modification. In this study, the proliposomes containing RSO and βC are referred to as Ps, while the modified formulations are denoted as sodium alginate–chitosan-modified proliposomes (SA-CS-Ps).Materials and methodsThe physicochemical properties, structural characteristics, thermal stability, microstructure, rheological behavior, storage stability, and oxidation kinetics of SA-CS-Ps were investigated and compared with those of unmodified Ps and CS monolayer-modified Ps (CS-Ps).ResultsThe particle size and turbidity of Ps increased with the addition of modification layers, reaching 563.73 nm and 0.697, respectively, for SA-CS-Ps. CS and SA formed a protective bilayer through electrostatic interactions, which preserved the spherical structure of Ps while enhancing its apparent viscosity and stress. Thermal stability analysis indicated that the phase transition temperatures of CS-Ps and SA-CS-Ps were elevated by 10.57 and 15.76 °C, respectively, compared with that of unmodified Ps. During storage, the retention rates (RRs) of RSO and βC followed the order SA-CS-Ps>CS-Ps>Ps, whereas malondialdehyde and peroxide values exhibited the opposite trend. Elevated temperatures accelerated oxidation, thereby compromising the protective effect of the carriers. After 24 d at 4 °C, SA-CS-Ps demonstrated superior stability, with malondialdehyde of 0.016 μg/mg, peroxide value of 2.697 mmol/kg, and RRs of RSO of 97.15% and βC of 96.37%. The oxidation kinetics conformed to a first-order reaction model.ConclusionsGiven its enhanced protection against degradation and stability, SA-CS-Ps represents a promising candidate for the delivery of sensitive bioactive compounds. This study provides a theoretical basis for the application of bilayer-modified proliposomes in functional food delivery systems requiring enhanced stability.