Estimation of the biofragmentability of packaging materials by an enzymatic method

To estimate either the susceptibility of packaging materials to enzymes or their potential biodegradability, experiments were conducted using cellulosic materials as models with Trichoderma viride cellulases. A classification of materials was carried out using two kinds of experiments. First, experiments were conducted to determine the percentage of biofragmentation after 5 h of incubation. Results were obtained on the global kinetics of the reducing sugars produced and on the percentage of hydrolysed glycosidic bonding (HGB) at the end of the experiment. This latter parameter allowed the study of the effect of material shape: pulverized or in film form. The classification from the decreasing values of the percentage of HGB obtained with pulverized substrates was: native cellulose > filter paper > noncoated cellophane # crystalline cellulose # paraffin-waxed paper > coated cellophane. Except for the experiment with the filter paper, the available surface area of a material had a significant effect, especially with the paraffin-waxed paper. The other experiments, based on shorter incubation times and entailing a rigorous kinetic methodology, allowed access to apparent kinetic parameters (denoted K'm and V'max). After a hydration of pulverized materials, the classification according to catalytic efficiency was the same as that based on the percentage of HGB, except for the paraffin-waxed paper. For the latter, the catalytic efficiency was as high as that on the filter paper.