Postdoctoral researcher University of Arkansas, United States
Abstract: Lipophilic bioactive food compounds have numerous health-promoting activities. However, they have low chemical stability and poor bioavailability. Therefore, the goal of this study was to develop a novel encapsulation method using 3D food printing to enhance the chemical stability of lutein. In this study, coaxial extrusion 3D printing was employed using lutein-loaded ethyl cellulose as the inner flow (core) material and corn starch as the outer flow (shell) material. The 3D printing parameters (i.e., layer height (0.4, 0.7, and 1 mm), ethyl cellulose (6, 8, and 10% w/v) and starch (9, 10, 11, and 12%, w/w) concentrations, and printing temperature (55, 65, or 75 °C)) were investigated and optimized for the best printability and encapsulation. The rheological properties of inks were determined prior to 3D printing. The 3D-printed shapes were investigated for their microstructure, storage stability, crystallinity, and surface chemistry. The best shape fidelity was obtained using the layer height of 0.7 mm as determined by their microCT images. In addition, starch concentrations of 10 and 11% provided the best printability, which, in turn, resulted in the highest storage stability of lutein. Encapsulation of lutein via 3D printing significantly increased the lutein retention indexes from 24 and 10% (control crude lutein) to 70 and 48% (encapsulated via 3D printing) after 21 days of storage at 25 and 50 °C, respectively. Overall, this dual-layered 3D food printing approach can be an alternative method to generating bioactive compound delivery systems to enhance their chemical stability for the food and pharmaceutical industries.