Musaceas comestible fruit production generates a high amount of fibrous residues that can be useful as raw material for composite industry. In this study, green composite materials without synthetic matrix from Musaceas agro-industrial fibrous residues as rachis have been developed. Rachis samples have been treated using a thermo-mechanical process: the steam explosion. Several treatment conditions controlled by severity parameter and compression conditions (temperature and pressure) were analyzed. According with mechanical results, composite flexural behaviour is enhanced by higher compression conditions. However, as shown by FTIR spectroscopy analysis, atomic force microscopy (AFM), sugar analysis by HPLC and PVT (pressure-volume-temperature) measurements severity generates important variations on rachis chemical composition, associated with the reduction of hemicellulose as xylose that affects the mechanical and physical behaviour of this type of composites.