The remaining fibrous residue of cassava starch extraction was characterized and used as film filler
in order to obtain an enhanced fully biodegradable starch-based composite. Film-forming gelatinized
cassava starch suspensions increased significantly their apparent viscosity and storage modulus with
filler addition, although no segregation of filler particles was observed. Homogenous films were obtained
from 3% w/w cassava starch film-forming suspensions including glycerol as plasticizer and the remaining
fibrous residue. Plasticizer concentration was optimized in reinforced starch films. SEM micrographs evidenced
that the filler was structurally incorporated in the matrix, although concentrations of 3% led
to more heterogeneous surfaces because of the presence of large size filler particles. Reinforced films
exhibited UV-barrier capacity and adequate water vapor barrier properties (14.6 ± 0.7 10−11 g/m s Pa)
and tensile strength (18.01 ± 0.19 MPa) when 25% w/w glycerol was added as plasticizer. Filler addition
reinforced the starch matrix increasing its mechanical resistance: 1.5% residue content increased
over 900% the films elastic modulus. Furthermore, the obtained eco-compatible materials could be heat
sealed, which indicates their suitability for packaging development. In conclusion, an integral approach
to cassava roots use has been proposed, expanding its scope and providing added value to the remaining
residue of starch extraction.