Lutein encapsulated in curdlan and sodium alginate by emulsification/internal gelation: Construction, characterization and stability of microcapsules.

In this study, microcapsules were constructed using the emulsification/internal ionic gelation method with curdlan (CUD) and sodium alginate (SA) as wall materials to enhance stability. Both one-way and response surface experiments were employed to optimize the microcapsule preparation process, resulting in an encapsulation rate of 81.36 %. XRD and DSC analyses indicated that CUD-SA composite microcapsules effectively encapsulate lutein (LUT) and enhance its stability. Rheological characterization demonstrated that the CUD-SA composite significantly enhanced gel strength, resulting in a more stable microcapsule structure. In addition, CUD-SA microcapsules exhibited significantly higher lutein loading (11.60 mg/g) compared to single-wall microcapsules. The stability assays demonstrated that CUD-SA-LUT microcapsules had higher retention under light, heat, and 4 °C storage conditions, as well as improved intestinal release rates. CUD-SA-LUT microcapsules demonstrated the lowest degradation constants and the longest half-life when compared to free LUT and single-wall microcapsules. These results demonstrated that the emulsification/internal gelation method is effective in enhancing the stability of lutein, thereby broadening their application in the food industry, and also serves as a reference for the application of CUD in the food sector.