The Production, Characterization, and Biodegradation Kinetics of Bioplastics From Starch Extracted From Ipomoea batatas and Manihot esculenta Tubers

ABSTRACT The accumulation of non‐biodegradable plastics is driving the search for environmentally friendly, low‐cost alternatives. This study investigated the production of biodegradable bioplastics using starch extracted from Ipomoea batatas and Manihot esculenta tubers. The tubers were pulverized, and starch was extracted. Bioplastic was produced by reacting the starch with ethanoic, methanoic, and propanoic acids in the presence of glycerol and water at 80°C for 25 min. The starch yield and the physicochemical, mechanical, and degradability properties of the bioplastics were determined. The results showed starch yields (57.5%; 52.26%), moisture content (12.38%; 13.74%), pH (6.9; 6.7), amylose content (20.4%; 20.67%) and amylopectin content (79.6%; 80.2%) for Ipomoea batatas and Manihot esculenta tubers, respectively. The mass of bioplastic produced was directly proportional to starch content and the number of carbon chains present in the organic acid. The mechanical properties showed that tensile strength was significantly ( p < 0.05) higher than that of the control, except for the 15 g bioplastic produced. Shear strength also showed a trend similar to tensile strength. The elongation/break properties significantly ( p < 0.05) increased in the methanoic acid‐derived bioplastic. The bioplastic degradation rates were (0.0059, 0.0056 and 0.0043 mg/ml/h) for Ipomoea batatas and (0.0099, 0.0098 and 0.0091 mg/ml/h) for Manihot esculenta‐derived biodegradable plastic, respectively , using Pseudomonas aeruginosa . The results of this study show that starches from Ipomoea batata and Manihot esculenta tubers could be a good source for bioplastic production because they are inexpensive, renewable, and readily biodegradable when disposed of in the environment.