Effect of Manufacturing Process and Xanthan Gum Addition on the Properties of Cassava Starch Films

• Published in: Journal of polymers and the environment Vol. 19; no. 3; pp. 739 - 749
• Main Authors: Melo, Cristina P. B., Grossmann, Maria V. E., Yamashita, Fábio, Youssef, Elza Y., Dall’Antônia, Luiz Henrique, Mali, Suzana
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.09.2011; Springer Nature B.V
• Subjects: Biodegradable materials; Biodegradation; Biofilms; Breaking; Cassava; Chemistry; Chemistry and Materials Science; Environmental Chemistry; Environmental Engineering/Biotechnology; Extrusion; Industrial Chemistry/Chemical Engineering; Manufacturing industry; Materials Science; Opacity; Original Paper; Plasticizers; Polymer Sciences; Pressure casting; Resins; Scanning electron microscopy; Starch; Starches; Stresses; Water vapor; Xanthan; Mechanical properties; Extrusion; Biodegradable films; Microstructure; Water vapor permeability
• ISSN: 1566-2543; 1572-8919; 1572-8900
• DOI: 10.1007/s10924-011-0325-1

The objective of this work was to manufacture biodegradable films by two different processes (casting and extrusion), from different combinations of cassava starch and xanthan gum. These films were produced by casting and by extrusion from six different starch-xanthan gum combinations (0, 2, 4, 6, 8 and 10% w/w), containing glycerol as plasticizer (20% w/w) and were also characterized according to their microstructure, optical, mechanical, and barrier properties. Scanning electron microscopy of the starch-xanthan gum extruded films showed reticulated surface and smooth interior, suggesting that xanthan was driven to the surface and gelatinized starch to the interior of the films during extrusion. Films manufactured by casting were entirely homogeneous. In general, casted films presented lower opacity and water vapor permeability and higher stress at break than films manufactured by extrusion. Xanthan gum addition affected mechanical properties of starch films, improving their stress and strain at break, especially for extruded samples, but these properties did not show stability at different RH conditions.