Enhancing lutein and anthocyanins stability and bioaccessibility through simultaneous encapsulation using coaxial 3D food printing

This study investigated the use of 3D printing to co-encapsulate, protect, and enhance the bioaccessibility of lutein and anthocyanins. Coaxial extrusion 3D printing in a spiral-cube geometry was utilized with lutein-loaded zein as the core material and anthocyanins-loaded corn starch paste as the shell material. The research examined various printing conditions, including starch concentrations of 10% and 11%, and printing temperatures ranging from 45 °C to 85 °C. A comprehensive analysis of the inks' properties, such as printability, viscosity, microstructural characteristics, storage stability, and bioaccessibility of the encapsulated compounds, was conducted. Encapsulated lutein showed only a 29-55% degradation rate after 21 days at 25 °C, while 97% of crude lutein was degraded under the same conditions. Similarly, encapsulated anthocyanins had 42-55% degradation rates depending on the 3D printing conditions compared to 70% for crude anthocyanins. Furthermore, the bioaccessibilities of encapsulated lutein (9.8%) and anthocyanins (37.5%) were significantly higher compared to their crude counterparts (1.5% and 20.3%, respectively). This innovative 3D printing encapsulation system effectively enhances the chemical stability and bioaccessibility of these model bioactive compounds, presenting a promising method for their integration into food products.