4D printing of edible insect snacks: Color changes with external pH stimulation

To increase consumers’ acceptance, food 3D/4D printing could be a suitable technology to develop attractive and nutritious insect foods. This study investigated the feasibility of making 4D printed snacks using cricket powder and purple potato puree as main ingredients, and the effect of ink composition on the 3D printing performance was investigated, while the color change caused by pH stimulation (4D) was measured. The results showed that the content of cricket powder and water in the ink significantly affected its rheological properties and printability. The color of the 3D-printed samples varied greatly with pH from red to green but was accompanied by high color stability. Additionally, the hardness, gumminess, adhesiveness, and cohesiveness of the 4D-printed snacks were significantly altered after the pH modification. This research opened a new window for the development of attractive 4D-printed insect snacks, which could be practically applicable of insect proteins for human foods.