Characterization of Biodegradable Films Made from Taro Peel (Colocasia esculenta) Starch.

Abstract

Studies of renewable polymers have highlighted starch's role to replace petroleum-based components to produce biodegradable films with plastic-like qualities. In this study, the novelty of taro peel starch (TPS) to produce such films using the casting technique is reported for the first time. A response surface method (RSM) approach was employed to optimize different concentrations of TPS (2.5-3.5%, w/w) and glycerol (25-35%, w/w) and investigate their effects on the physico-mechanical and water barrier properties of TPS films. TPS films showed a positive linear effect (p < 0.05) for thickness (0.058-0.088 mm), opacity (1.95-2.67), water vapor permeability (0.06-0.09 g∙m/m2∙kPa∙h), and cubic effect (p < 0.05) for moisture content (0.58-1.57%), which were linked to high starch concentrations when plasticized with glycerol. X-ray diffraction analysis of TPS films depicted "amorphous"-type crystalline structure peaks at 19.88°, while the thermogravimetric analysis of the film samples exhibited 75-80% of the weight loss of TPS film in the second phase between temperatures of 300 °C to 400 °C. All films exhibited homogenous, transparent surfaces with flexibility, and completely degraded in 5 days in simulated river water and composting soil environments, which confirmed TPS as a promising film polymer in food packaging.