Exploring the Most Suitable Starch Sources for Bioplastic Production 

The objective of the project is to determine the most suitable starch for preparing a starch-based bioplastic that mimics traditional plastic while being biodegradable. Around half of the bioplastics in use currently are derived from starch, which is a polymer made up of repeating glucose units, amylose (linear) and amylopectin (branched). The degree of crystallinity significantly affects the hardness and density of the plastic. The formation of amylose molecules during polymerization creates a crystalline structure, while amylopectin results in an amorphous structure. Different starch sources have varying ratios of amylose and amylopectin, resulting in bioplastics of varying strength. Higher amylose concentration in starch leads to a stronger bioplastic. Bioplastics made from various starch sources such as Rice, Corn, Wheat, Potato, and Cassava were tested for flexibility, opacity, water resistance, biodegradability, and strength.

The rice-based bioplastic had the highest amylose content and was the strongest among the grain-based samples. In the tuber category, the arrowroot-based sample with the highest amylose content was the strongest. This suggests that higher amylose content results in a stronger bioplastic. However, the corn-based bioplastic, even though it has higher amylose content than arrowroot and Cassava, was weaker. This could be due to the higher fiber content in arrowroot and Cassava flour, resulting in increased strength.

Based on the results, rice-based bioplastic closely resembles traditional plastic compared to other samples.