3D Printing of smart labels with curcumin-loaded soy protein isolate

Lutein encapsulation into dual-layered starch/zein gels using 3D food printing: Improved storage stability and in vitro bioaccessibility

The ability of 3D printing to encapsulate, protect, and enhance lutein bioaccessibility was investigated under various printing conditions. A spiral-cube-shaped geometry was used to investigate the effects of printing parameters, namely zein concentration (Z; 20, 40, and 60 %) and printing speed (PS; 4, 8, 14, and 20 mm/s). Coaxial extrusion 3D printing was used with lutein-loaded zein as the internal flow material, and corn starch paste as the external flow material. The viscosities of the inks, microstructural properties, storage stability, and bioaccessibility of encapsulated lutein were determined. The sample printed with a zein concentration of 40 % at a printing speed of 14 mm/s (Z-40/PS-14) exhibited the best shape integrity. When lutein was entrapped in starch/zein gels (Z-40/PS-14), only 39 % of lutein degraded after 21 days at 25 °C, whereas 78 % degraded at the same time when crude lutein was studied. Similar improvements were also observed after storing at 50 °C for 21 days. Furthermore, after simulated digestion, the bioaccessibility of encapsulated lutein (9.8 %) was substantially higher than that of crude lutein (1.5 %). As a result, the developed delivery system using 3D printing could be an effective strategy for enhancing the chemical stability and bioaccessibility of bioactive compounds (BCs).

Physico-Chemical Characteristics of pH-Driven Active Film Loading with Curcumin Based on the Egg White Protein and Sodium Alginate Matrices

The low solubility and stability of fat-soluble curcumin in water limit its application in active packaging. This study explored the use of a pH-driven method to investigate the preparation and enhancement of the performance of films loaded with curcumin in a matrix of sodium alginate (Alg) and egg white protein (EWP). In this study, the EWP, Alg, and curcumin primarily bind through hydrogen bonding, electrostatic interactions, and hydrophobic interactions. Compared to EWP films, the films loaded with curcumin through the pH-driven method exhibited enhanced extensibility and water resistance, with an elongation at break (EB) of 103.56 ± 3.13% and a water vapor permeability (WVP) of 1.67 ± 0.03 × 10-10 g·m/m2·Pa·s. The addition of Alg improved the encapsulation efficiency and thermal stability of curcumin, thereby enhancing the antioxidant activity of the film through the addition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, which resulted in 106.95 ± 2.61 μg TE/g and 144.44 ± 8.89 μg TE/g, respectively. It is noteworthy that the detrimental effect of Alg on the color responsiveness of films containing curcumin has also been observed. This study provides a potential strategy and consideration for the loading of low water-soluble active substances and the preparation of active packaging.

Gelatin/polychromatic materials microgels enhanced by carnosic acid inclusions and its application in 2D pattern printing and multi-nozzle food 3D printing

Natural polychromatic biomaterials (like carminic acid and gardenia yellow) possess coloring merits and functionality, but are instable under light and heat. Self-assembly of gelatin and polychromatic materials could be induced by carnosic acid inclusions, illustrating great potential in food application. Antioxidant properties, pigment retention rates, UV irradiation stability, rheological properties, and physical resistances (oil, ethanol, heat and microwave) of samples were improved by carnosic acid inclusions, owing to the newly formed hydrogen bonding and electrostatic interactions (UV spectrum, particle size, zeta potential, FTIR, XPS and SEM). The improved properties contributed to the 2D printed pattern stability and the applicability for producing specialized products with high printability and fastness. On the basis of Subtractive Color-Mixing Principle, further three-dimensional dyeing microgel systems were built and modulated; it could functionalize bean paste/carboxymethyl-cellulose food systems, maintain the excellent self-supporting ability & mechanical strength, and promote single/dual-nozzle 3D printing application. Therefore, the self-assembled gelatin/polychromatic materials/carnosic acid microgel samples could not only achieve outstanding 2D printed pattern stability, and could be also promisingly applied in single/dual-nozzle 3D printing for modern innovative, creative food fields.