Meat analog production through artificial muscle fiber insertion using coaxial nozzle-assisted three-dimensional food printing

In this study, we propose a method for the texture of meat analogs through artificial muscle fiber insertion based on cross-linkable hydrocolloids using a coaxial nozzle-assisted three-dimensional (3D) food printer. Hydrocolloid-based muscle fiber simulation material was prepared in 2.5-5% solutions with different formulations of kappa and iota carrageenan (CG), sodium alginate (SA), and glucomannan (GM). During the coaxial nozzle-assisted 3D food printing process, all samples were cured using K+ and Ca2+. The fiber solution before post-processing formed a gel by SA ionic bonding; subsequently, the gel strength increased due to CG structural changes and the synergy between CG and GM. Therefore, with respect to the rheological properties, all samples, except for CG(1.5)GM(0), formed a hard gel. However, concerning the texture properties, only CG(1.5)GM(1.5) and CG(2.5)GM(1.5) displayed an elastic strength comparable to that of actual meat due to GM elastic gel formation, and CG(2.5)GM(1.5) displayed the highest hardness. Post-processing the product quality was investigated by determining shrinkage and cooking loss. We found that transversal shrinkage was higher than longitudinal shrinkage, and cooking loss was reduced in the samples. These results were visibly related to the final gel strength. In this study, we successfully tested the embodiment of texture, which is a challenge for alternative meat, using a coaxial nozzle-assisted 3D food printer. This system uses hydrocolloids as a carrier to insert functional materials, and we confirmed the possibility of applying it to other foods that require texture embodiment.