STARCH FOAM TRAYS DEVELOPMENT FOR BIODEGRADABLE FOOD PACKAGING USES

Starch foam materials are an environmentally friendly alternative to EPS as they are non-toxic and biodegradable materials. However, water resistance, good flexibility, and tensile and flexural strength are necessary for uses such as food and non-food packaging, which starch foams lack compared to petroleum-based derivatives. Furthermore, vegetable pomace is rich in lignocellulose compounds and can improve some of the properties of these packaging. The aim is to develop cassava starch foam trays reinforced with malt bagasse (BM). The antihumectant tricalcium phosphate (0-5%), plasticizer glycerol (0-5%) and malt bagasse reinforcement (0-10%) were used in a complete experimental design 23 to develop starch foam trays. The starch foam trays were produced by thermal expansion in molds at 180°C for 4 min. Density (g/cm3), hygroscopicity (%) and humidity (%), flexural strength (Mpa) and maximum deflection (mm), by three-point breaking test and tensile strength (MPa), elongation (%) and tensile modulus of elasticity (MPa). The density varied from 0.1577 to 0.2356 g/cm3, with the unfilled foam trays having a lower density than the filled ones. Tensile strength ranged from 0.369 MPa to 1.454 MPa, being influenced by the addition of tricalcium phosphate and malt bagasse. The treatment that did not contain phosphate resulted in lower tensile strength and elastic modulus. The elongation ranged from 0.45 to 1.45% and the elastic modulus from 46.34 to 126.64 MPa. Flexural strength (0.996 to 1.500 MPa) and deflection (2.09 to 3.35 mm) were influenced by the amount of BM and phosphate, treatments with higher humidity (5 and 6%) resulted in more flexible trays. The interactions between phosphate, malt bagasse and glycerol require further studies, as phosphate positively affected the mechanical properties, but did not affect hygroscopicity (%). Biodegradable cassava starch foam trays filled with lignocellulosic waste can be a good alternative to petroleum-based packaging.