Fabrication and characterization of edible inks for 3D printing of dysphagia foods based on corn starch stabilized by calcium ions and hydrocolloids

Different starch modification methods have been proposed to broaden the application of starch-derived ingredients in the field of 3D printing. In this study, the effects of different concentrations of anionic hydrocolloids (xanthan gum and sodium alginate) and calcium ions (Ca2+) on the structural and physicochemical properties of corn starch-based edible inks were investigated. The presence of the Ca2+-crosslinked anionic hydrocolloids enhanced the gelatinization, rheological, and thermal properties of the corn starch, with the xanthan gum showing the best improvement. The crystal structure of the starch granules disappeared after gelatinization in both the presence and absence of the anionic hydrocolloids. However, the starch in the composite hydrogels had a more compact and uniform microstructure than that in the pure starch hydrogels. The observed improvements in the functional performance of the starch in the composite hydrogels were mainly attributed to alterations in noncovalent interactions, such as hydrogen bonding and ion bridging. The starch-hydrocolloid hydrogels exhibited better printing performance than starch hydrogels in 3D printing applications. Consequently, they have potential in the development of foods for people suffering from dysphagia. This research shows that anionic hydrocolloids can be used to enhance the functional performance of starch-based edible inks in the field of 3D food printing.