Incorporation of Rice Starch Affecting on Morphology, Mechanical Properties and Water Vapor Permeability of Glutelin-based Composite Films

摘要

Protein is a by-product of rice starch production. The major component of rice protein found in endosperm is glutelin, an alkali-soluble protein. Pure glutelin film could not peel off from the casting plate; however, glutelin films containing starch were easily removed from the plate. Various ratios of rice starch and glutelin at 100:0, 92:8, 75:25, 50:50 and 25:75 (w/w) were applied for casting film. Sorbitol was used as a plasticizer. Morphology was studied by scanning electron microscope. The mechanical properties and water vapor permeability (WVP) were evaluated. The results were found that rice starch and glutelin-based composite films became thinner with smoother surface as starch content increased. Elongation and flexibility of composite films containing glutelin could be improved by incorporation of rice starch at a considerable amount without affecting on tensile strength and WVP. Practical Applications This research had an objective to study the surface morphology, mechanical properties and WVP of composite films based on glutelin (by-products from producing rice starch) and rice starch. Those properties are important for the applications used as edible films/coatings. Edible films and coatings could be used to protect the product from mechanical damage, physical and chemical. In this paper, we did not add any antimicrobial agent. So, this film cannot protect the product from microbiological activities. The applications of edible films and coating have been successfully applied in fresh foods and processed foods.