Nanoliposomal Encapsulation of Red, Yellow, and Orange Natural Pigments from Monascus ruber: Characterization, Stability, and Biological Activities.

Monascus pigments, a type of natural edible colorant, are extensively utilized in the food and health supplements industry. However, these pigments tend to be unstable during processing and storage. Thus, this study aims to prepare nanoliposomes of the Monascus three pigments and evaluate their properties and bioactivities. Three types of pigments (red, orange, and yellow) produced by Monascus ruber strain SRZ112 were extracted and purified then encapsulated into nanoliposomes. The prepared nanoliposomes were characterized by DLS, FT-IR, and TEM analyses. The obtained results showed that the three respective nanoliposomes have different polydispersity indexes (0.243, 0.187, and 0.202), zeta potentials (-21.79, -19.26, and-21.61 mV), and a range of particle sizes (85.31, 90.67, and 86.66 nm) with spherical unilamellar vesicles dependent on the prepared liposome type. The prepared nanoliposomes' pH, thermal, and storage stabilities were studied and compared to the free pigments. Moreover, the prepared nanoliposomes' antimicrobial, anti-inflammatory, antioxidant, and cytotoxic bioactivities were compared to the free pigments and evaluated. The prepared nanoliposomes in this study showed enhanced functionalities and bioactivities more than the free pigments. This is the first report on the nanoencapsulation of Monascus red, yellow, and orange pigments and the evaluation of their bioactivities. The achieved results in this study indicate the possibility of their exploitation in the cosmetic, pharmaceutical, and functional food industries.