Analyzing the most promising innovations in food printing. Programmable food texture and 4D foods

With the increase of the published scientific results, 3D food printing is suddenly growing with many opportunities and possibilities to contribute to the current challenges of the food system. We present a brief review focused on two promising applications that are drawing where and how food printing is currently evolving: 4D food printing and the creation of programmable food texture. We found an interesting number of scientific documents regarding 4D foods generating changes of colour, shape, dimension, aroma and nutritional content. Among others, these changes are activated by many external stimuli such as acid/alkaline conditions, the anisotropic behaviour of printed materials during drying, but further experiments and discussions are still needed considering the effect of such stimuli on other important points such as safety and quality parameters. Contrarily, very few results have been published on the programmable food texture, but these few allow us to glimpse breakthrough innovations capable to completely renew the texture perception and mechanical properties of food products with extreme benefits for market innovation and consumer's desires and needs such as the creation of a fragile structure for people suffering dysphagia.