Optimization of Cassava Starch-Based Biodegradable Films With Garcinia kola Oil and Cocos nucifera L. Microfibers Using Response Surface Methodology

Starch-based films have low water resistance and poor mechanical properties. This study aimed to optimize the properties of biodegradable films based on cassava starch reinforced with Garcinia kola oil and Cocos nucifera L. microfibers. To this end, OléKanga cassava starch, G. kola oil, and C. nucifera L. microfibers were used to produce an optimized packaging film using response surface methodology (RSM). The desirability function subsequently determined an optimal formulation. The results showed that adding microfibers, and oil increased thickness by 77%, reduced water content by 43%, decreased water solubility of the film by 46%, and reduced water vapor permeability (WVP) of the starch-based films from 955 × 10⁻¹³ to 5.15 × 10^–13 g·Pa⁻¹·s⁻¹·m⁻¹. In other words, there was a 99% increase in the film’s water vapor barrier. However, elongation was reduced with the addition of microfibers. The addition of G. kola oil increased film opacity from 1.56 ± 0.05 to 4.26 ± 0.08 A·mm⁻¹ and reduced the breaking strength by 62%. An optimal film formulation was determined using the desirability function, with 4 g OléKanga cassava starch, 30% glycerol, 5% C. nucifera L. microfibers, 25% G. kola oil, and 5% lecithin. The properties of the films were improved by adding G. kola oil and C. nucifera L. microfibers to the starch matrix.