Preparation and Performance Evaluation of Plant Protein-Based Maize Yellow Pigment Microcapsules

To overcome the problems associated with maize yellow pigment (MYP) such as poor water solubility, instability, and low bioavailability, MYP was microencapsulated with different plant-based proteins, pea protein isolate (PPI), hemp protein (HP), or soybean protein isolate (SPI) combined with sodium alginate (SA) as a mixed wall materials or maltodextrin as a single wall material. The encapsulation efficiency, physicochemical properties, particle size, thermal stability, microstructure, in vitro digestion characteristics, and antioxidant capacity of the microcapsules were evaluated, and their protective effect on H₂O₂-induced oxidative damage in ARPE-19 cells was investigated. The results showed that microencapsulation of MYP improved its solubility, bioavailability and antioxidant activity. Microcapsules with MYP concentrations in the range of 375-1125 μg/mL did not affect the viability of ARPE-19 cells, and showed superior cellular antioxidant effect in the H₂O₂-induced oxidative damage model. The three mixed wall materials exhibited different functional characteristics. Compared with those prepared with the other wall materials, PPI-SA microcapsules showed higher encapsulation efficiency, lower water content, smaller particle size, and better fluidity and stability.