Effect of Acetic Acid and Citric Acid Modification on Biodegradability of Cassava starch Nanocomposite Films

Abstract

The effect of acetic acid and citric acid modification of cassava starch on the biodegradability of their films reinforced with lignin and nanofiber was determined. Cassava starch was first modified with acetic anhydride and citric acid, characterized, filled with lignin and nanofiber to produce the films. Biodegradation studies were based on determinations of water absorption capacity, soil burial, enzyme degradation and reducing sugar (glucose). Results showed that great variations in water absorption capacities, weight loss in soil, enzyme degradation and reducing sugar were observed with TPS (Thermoplastic starch) having the fasted and highest water uptake, weight loss in soil, enzyme degradation and glucose equivalents while the modified starches had the slowest and least values compared with the native starch. Thus, acetic anhydride and citric acid modification improved the cross linking of the native starch thereby making it less biodegradable but not affecting its overall biodegradability.

Optimization of Lignin-Nanofiber-Filled Thermoplastic Starch Composite Film Production for Potential Application in Food Packaging

“…Before being introduced into the plasticised starch mixture, the nanofibers were sonicated for 10 min by using a 60 W rated Sonicator. The mixture of dispersion was then cast into a mold and oven-dried at 50 o C using a still-air oven for 18 h in order to obtain dry lignin-nanofiber-filled thermoplastic starch composite films [21,22], whose average thickness was found to be 0.12mm. The control (TPS) sample was also prepared using the same process mentioned above, except that there were no fillers added to it.…”

“…The film samples were removed from distilled water after intervals of 1, 3, 5, 7, 9 and 11 h and, after wiping off the excess water on their surfaces with tissue, their weights were determined. The water absorption capability (WAC) was thus calculated using Equation 5 [21,25]:…”

Study of the Physical and Mechanical Properties of Thermoplastic Starch/Poly(Lactic Acid) Blends Modified with Acid Agents

“…This prevents-or makes starch less prone to-retrodegradation [18]. In the research conducted by Abdul Rasheed et al [19], it is evident that the modification of cassava starch with acetic anhydride and citric acid reduces the water absorption capacity, thereby reducing its degradation rate without affecting film biodegradability. Other fatty acids have been used to modify starch, such as oleic acid, whose main effect is reflected in the decrease in the glass transition temperature [18,20].…”