Paper presented at the 52nd CFCS Annual Meeting, Guadeloupe, July 10-16, 2016
MAKING OF BIOPLASTIC FROM AGRICULTURAL WASTE PRODUCT Annesa Ali and Dr. Puran Bridgemohan Centre for Biosciences, Agriculture and Food Technology, The University of Trinidad and Tobago puran.bridgemohan@utt.edu.tt Keywords : Starch, yield, Bioplastics, agricultural waste Abstract Bioplastics are made from organic biomass sources instead of petroleum. This project aimed to produce a bioplastic material utilizing an agricultural waste product as well as to assess the starch yield of the waste peel. It is an attempt to use natural plastics to replace synthetic plastics and to reduce the negative environmental impacts and the extensive consumption of non-renewable resources. This study used the peel of Manihot esculenta (cassava) as the agricultural waste source. The experiment was performed in two steps; extraction of starch from raw material and the polymerization reaction. From this extraction process, the waste peel yielded 20.93% of starch., which accounted for 15.90% of the total (flesh and peel) extracted amount. The extracted starch from the waste peel was used to successfully produce a bioplastic. Materials and methods Starch extraction and polymerization methods, as illustrated in Figure 1, were taken from RSC Advancing the Chemical Sciences. Cassava tubers were used in this study. For the extraction process, 18 866g of sample was peeled and the weights of both flesh and peel were recorded. The flesh and peel were blended separately with water, drained and allowed to settle. It was later decanted and allowed to dry. The dried samples were then powdered using a commercial mill to achieve the desired consistency. The starch yields in weight were noted for both.
Figure 1: Starch extraction and polymerization (from RSC Advancing the Chemical Sciences)
For the polymerization process, 25cm³ of water was poured into a beaker. Added to this was 2.5g of starch from the peel and 3cm³ hydrochloric acid. The mixture was then brought to a gentle boil for 15 minutes and then neutralized using sodium hydroxide. The neutralized mixture was poured into a petri dish and allowed to dry. (Method adapted from “Making a Plastic from Potato Starch - Making the Plastic”, n.d.). Main results Results show that 6399.69g of dried cassava tubers produced 1446.05g of starch. Additionally, 1215.94g (19% by weight) was extracted from the flesh and 230.11g (20.9% by weight) was extracted from the waste peel. The starch from the waste product accounted for 15.9% of the total starch extracted (refer to Figure 2).
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