Cassava (Manihot esculenta), is a perennial plant, normally cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous roots. The tuberous roots of cassava are a rich source of fibre (soluble and insoluble) and are predominately consumed in a boiled form. The peel of the tuber also serves as food for livestock such as sheep and goats. Starch extracted from cassava has found uses in various industries and the fibre is being used in biodegradable plastics for disposables used in packaging and in homes.
Biodegradable Plastics from Cassava Starch:
Petroleum-based plastics are a growing concern because of their accumulation in the environment. They are not biodegradable and are constant source of pollution due to irresponsible disposal. Plastic foams are used extensively as cushioning materials for the protection of fragile products during transportation and handling. They are normally limited to these uses since they have many other purposes. Plastic foams with biodegradable polymers are a preferable and a much sought after choice compared to petroleum-based plastics. These biodegradable polymers can degrade in the environment by action of microorganisms in the presence of moisture. Crops like Cassava provide ample sources of biopolymers (starch, protein, and cellulose) which can be readily used to make biodegradable plastics. Commercially available starch foams have successfully replaced polystyrene foams. However, these foams disintegrate immediately when exposed to moisture, limiting their use in environments that are not moisture-free.
Researchers (S. Bhatnagar and A. Hanna) have developed a process to make starch-based foams replacing as much as 70-80% of the plastic with starch without compromising the functional properties of the end product .These foams had much better water resistance than did starch foams made from hydroxypropylated starch and polyvinyl alcohol.