Use of malt bagasse to produce biodegradable baked foams made from cassava starch

Abstract

Malt bagasse, a byproduct of the brewing industry, was used to produce biodegradable foam trays made from cassava starch using a baking process. These foams were prepared with different concentrations of malt bagasse (0–20%, w/w) and then were characterized according to their microstructure, physical and mechanical properties. The trays produced with 5 and 10% (w/w) malt bagasse had the highest production yields (100%), the trays thicknesses ranged from 2.16 to 2.24mm and densities ranged from 0.415 to 0.450g/cm3. There was a good distribution of the malt bagasse throughout the polymeric matrix, which had an amorphous structure. The variation in the relative humidity (RH) from 33 to 58% did not affect the mechanical properties of the produced foams, but the stress at break decreased and the strain at break increased when the trays were stored at 90% RH. As demonstrated by the sorption isotherm data, the incorporation of malt bagasse at 10% w/w resulted in a decrease in the hygroscopicity of starch foams. The addition of bagasse at concentrations up to 15% w/w decreased the initial water adsorption rate of the trays. The produced trays can be a viable alternative for packing dry foods, reducing the use of petroleum based materials.