Preparation and Stability Assessment of Docosahexaenoic Acid-Acylated Astaxanthin Diester Liposomes

Docosahexaenoic acid-acylated astaxanthin diester (AST-2DHA) offers multiple nutritional benefits, however, its stability is limited by susceptibility to degradation under light and oxygen during storage and application. To address this, the present study developed liposomes using AST-2DHA as the core material combined with plant-derived components. The resulting AST-2DHA liposomes (AST-DHAs-PLO) were systematically evaluated for their physicochemical properties. The results showed that AST-DHAs-PLO exhibited a mean particle size of 97.8 ± 2.01 nm, a polydispersity index of 0.234 ± 0.01, and a zeta potential of –3.14 ± 0.77 mV, indicating uniform particle size distribution and good dispersibility. Transmission electron microscopy revealed that AST-DHAs-PLO exhibited a spherical morphology with a smooth, regular surface and no visible collapse. Differential scanning calorimetry demonstrated superior thermal denaturation resistance. Fourier transform infrared spectroscopy confirmed effective encapsulation, with AST-2DHA successfully embedded within the liposomal structure. Furthermore, AST-DHAs-PLO exhibited high retention rates and maintained good stability under various environmental conditions, with a retention rate exceeding 68% after 15 days of storage at 4°C. These results suggest that liposomal encapsulation can substantially improve the stability of AST-2DHA and offer a promising delivery strategy for functional food applications.