With plastics resistance to degradation in nature and lack of effective recycling practice, it has resulted in a serious threat to the environment. Concerns about the environmental pollution caused by plastics have led to serious demands for biodegradable plastic materials made from renewable source. Starch is a biopolymer that has been being an attractive alternative for packaging material. A general overview on the microstructures of starch is given in this essay. The modified methods in biodegradable starch-based films are reviewed, which include physical, chemical and enzymic modification. Physical modification involves ultrasonic, mechanical treatment and addition of additives, such as plasticizer and coupling agent. Chemical modification consists of etherification, esterification, cross-linking, grafting and oxidation. Enzymic modification includes debranching reaction of starch debranching enzyme which contains pulullanase and isoamylase. The biodegradation of starch-based films and the prospects of their future are also detailed.
Oligosaccharide and Substrate Binding in the Starch Debranching Enzyme Barley Limit Dextrinase
