Muscle fibrous structural design of plant-based meat analogs: Advances and challenges in 3D printing technology

Background Plant-based meat analogs (PMAs) as important alternatives to animal meats that have been proposed in recent years in response to sustainable development strategies. It has gained extensive attention due to issues associated with animal meat production including environmental stress, ethical concerns, and effects on human health. However, the muscle fibrous structure is a significant indication for simulating real animal meat. 3D printing technology has been widely used as an innovative and effective tool for the production of PMAs, but there are several challenges regarding how to use 3D printing technology for the design of muscle fibrous structures. Scope and approach This review mainly focuses on the advances in the fibrous structure improvement of PMAs using 3D printing technology. The structural characterization of animal meat myofibrils and the fiber formation mechanism of plant protein were described, and various methods (thermal extrusion, freeze structuring, high-temperature conical shearing, electrospinning, and wet spinning) of processing PMAs were compared with 3D printing technology. Key findings and conclusions It was observed that the peptide, disulfide, hydrogen, hydrophobic, and ionic bonds, as well as the protein structure changes under different processing are the major reasons of PMAs’ fibrous structure formation. Therefore, 3D-printed PMAs with fibrous structures can be produced by selecting appropriate proteins or modifying protein structures, designing suitable 3D printers and running with the optimal parameters. Also, we put forward an interesting and effective way to produce fibrous PMAs through 3D printing combined with twin-screw extrusion or wet spinning, it is expected to create fibrous structures that are closer to real meat in the future.