BIODEGRADATION OF STARCH-BASED MATERIALS

The aim of this study was to compare three different test methods for assaying the biodegradability of starch-based materials. The materials tested included some commercial starch-based materials and thermoplas tic starch film prepared by extrusion from native potato starch and gl ycerol. Enzymatic hydrolysis was performed using excess Bacillus liche niformis alpha-amylase and Aspergillus niger glucoamylase at 37 degree s C. The degree of degradation was assayed by measuring the dissolved carbohydrates and the weight loss of the samples. The head-space test was based on carbon dioxide evolution using sewage sludge as an inocul um. The composting experiments were carried out in an insulated commer cial composter bin. The degradation was evaluated visually at weekly i ntervals, and the weight loss of the samples was measured after compos ting. Good correlation was found among the three different test method s.