Enhancing 3D printability of pureed food by addition of hydrocolloids

Abstract

In order to encourage dysphagia patients to increase their food and liquid intake, 3D printing can be employed to shape broccoli puree into more appetizing 3D structures. However, most pureed food inks require the addition of thickening or gelling agents so that the printed structure can hold its shape after the printing process. Edible hydrocolloids are therefore a perfect candidate for such an application. In this review, we looked at recent scientific work in the 3D food printing community with an emphasis on how researchers modified their starting food materials to make them printable. Some examples of such additives include starch, pectin, gelatin, nanocellulose fibres, alginate and also carrageenan. Furthermore, we want to share results of our own preliminary study, where a mixture of low-acyl gellan gum (LG) and locust bean gum (LB) was added to broccoli puree to enhance 3D printability. 3-step oscillatory strain tests were then conducted to mimic the rheology changes at the printing nozzle. It was found that when using a mixture of LG and LB, a 49.6% drop in storage modulus (G’) could be achieved upon application of 10% strain. Upon removal of the strain, a 65.1% recovery of G’ could be achieved. The visual appearance of the broccoli puree with this mixture of hydrocolloids was also deemed to be the closest to the originally intended 3-cm cube shape. Future work will include further optimising the mixing ratio in smaller steps and also, minimising the total hydrocolloid content while retaining acceptable printability and print fidelity, with minimal taste compromise.