Encapsulation of astaxanthin in zein/sodium carboxymethyl cellulose composite nanoparticles with increased stability and antioxidant activity

Astaxanthin (AST), a natural lipid-soluble carotenoid, exhibits numerous advantageous biological activities. However, its widespread utilization is limited by strong hydrophobicity and poor stability. To overcome these limitations, the AST-loaded zein/sodium carboxymethyl cellulose composite nanoparticles (AZC NPs) were prepared primarily via electrostatic interactions and hydrogen bonding. AZC NPs showed a spherical shape with a mean size of approximately 250 nm. As expected, due to its high negative zeta potential (−33.10 ± 2.72 mV) and the decoration of sodium carboxymethyl cellulose, AZC NPs demonstrated excellent stability against different environmental stresses. Notably, AZC NPs possessed sustained-release behavior and better antioxidant activity compared to those of free AST. These findings suggested that AZC NPs had significant application potential in the food industry. Fig. 1 . Schematic illustration for the formation mechanism of AZC NPs. Highlights • The composite nanoparticles were successfully prepared to encapsulate astaxanthin. • Sodium carboxymethyl cellulose improved the stability of the nanoparticles. • The release of astaxanthin from the nanoparticles occurred in a sustained manner. • The fabricated nanoparticles enhanced the antioxidant activity of astaxanthin.