Additive Manufacturing (AM) opens new perspectives for biopolymers to obtain functional parts, like biomedical devices, by exploiting their biocompatibility and resorbability. Plasticized materials from zein, a storage protein from maize seed endosperm, display thermomechanical properties that could match with Fused Deposition Modeling (FDM). The objective of this work was to evaluate their thenno-rheological behavior and their structural modifications during processing. 20% glycerol was added to conunercial zein, containing naturally about 4% lipids and 5% water. After storage at intermediate relative humidity (RH=59%). its glass transition temperature, measured by DSC, was T(g)=42°C. The main mechanical relaxation, measured by DMA, was found at Tα=50°C, leading to a drop of the elastic modulus from E'=1.1GPa, at ambient temperature, to E'=0.6MPa at Tα+100°C. These values are in a similar range as those of standard polymers used for AM-FDM processing, such as PLA and ABS. The structure of zein was characterized at different scales by SDS-PAGE, reversed-phase HPLC, FTIR and WAXS, at each processing stage: (i) the initial formulation of the plasticized powdery material, (ii) after extrusion at 130°C for shaping printable filaments, and (iii) after deposition through the 3D printer nozzle (Ø(nozzle)=0.5mm, T(printing)=130°C, v(printing)≈10mm/s). The presence of disulfide bond cross-links was evidenced in extruded filaments and the level after printing. WAXS showed that, in these conditions, no molecular orientation was obtained in the deposited material. By tuning zein-based printable compositions, these results open the field of their processing as resorbable printed parts, with a controlled geometry and a designed tridimensional structure.