Cellulose nanocrystals-gelatin composite hydrocolloids: Application to controllable responsive deformation during 3D printing.

Three-dimensional (3D) food printing is an effective technology for creating food designs with complex appearances and customized nutritional profiles. However, controlling the deformation of 3D printed foods during processing remains a challenge. Here, a food hydrocolloid with customizable designs during heating and dehydration was designed using cellulose nanocrystals (CNC) and gelatin (G). The resultant cellulose nanocrystals-gelatin (CNC-G) hydrocolloid exhibited favorable rheological characteristics for three-dimensional (3D) printing. 3D printing allows the controlled oriented alignment of the CNC particles within the hydrocolloid along the printing direction, endowing the CNC-G hydrocolloid with highly anisotropic structures. This anisotropic property can cause a strain mismatch during dehydrated food processing, leading to a specific deformation of the hydrocolloid. By adjusting the 3D printing parameters and intentionally designing of the 3D printed structures, the alignment degree of CNCs within the hydrocolloid can be controlled, and thus, its deformation can be programmed. The customizable deformation of CNC-G hydrocolloid during food processing was deliberately designed through printing, and its adaptability and flexibility are demonstrated through the "flapping" of a butterfly and the "blooming" of a four-leaf clover. The flexibility and customizability of CNC-G hydrocolloid in 3D printing provide a new strategy to achieve deformation and precise control of 3D printed foods during processing. [Display omitted] • A responsive food hydrocolloid prepared through 3D printing. • The CNC particles in the hydrocolloid align under shear force during 3D printing. • The anisotropic structure makes the food hydrocolloid deform during dehydration. • The deform actuations of hydrocolloid can be controlled by printing parameters. [ABSTRACT FROM AUTHOR]