Extração e caracterização do amido do fruto-do-lobo (Solanum lycocarpum St. Hil.) e elaboração de filmes biodegradáveis

Abstract

Non biodegradable packing plastics have become an environmental problem and a new way of solving this problem is the use natural polymers in a production of biodegradable materials. Biodegradable films can be mainly produced from polysaccharides, particularty starch. The objectives of this work were to extract and characterizing starch from Solanum lyocarpum and use it as a starchy source for biodegradable films. The characteristics of starch and films were evaluated according to their physicochemical properties. The films were elaborated according to the casting technique using 2% of starch and glycerol (5, 10, 15 and 20% v/v, based on starch concentration). Film samples were analyzed concerning its thickness, mechanical tests (traction and compression) and optical properties. Pure starch content is 99,39%. Concerning its morphology, starch granules presented spherical sharpe with angled edges and average of 12 a 15µm size showing crystalline type B. Gelatinization temperature ranged from 67,20 to 69,50°C and high thermal stability and considerable tendency of retrogradation. Film samples presented thickness varying from 0,047 a 0,072 mm according to glycerol concentration. The physics properties of films was influenced by glycerol content. In relation to starch crystalinity, films showed a typical amorphous structure, however it was observed a small crystal structure at 21,35º (2 theta).