ESTIMATION OF THE BIOFRAGMENTABILITY OF PACKAGING MATERIALS BY AN ENZYMATIC METHOD

To estimate either the susceptibility of packaging materials to enzyme s or their potential biodegradability, experiments were conducted usin g cellulosic materials as models with Trichoderma viride cellulases. A classification of materials was carried out using two kinds of experi ments. First, experiments were conducted to determine the percentage o f biofragmentation after 5 h of incubation. Results were obtained on t he global kinetics of the reducing sugars produced and on the percenta ge of hydrolysed glycosidic bonding (HGB) at the end of the experiment . This latter parameter allowed the study of the effect of material sh ape: pulverized or in film form. The classification from the decreasin g values of the percentage of HGB obtained with pulverized substrates was: native cellulose > filter paper > noncoated cellophane # crystall ine cellulose # paraffin-waxed paper > coated cellophane. Except for t he experiment with the filter paper, the available surface area of a m aterial had a significant effect, especially with the paraffin-waxed p aper. The other experiments, based on shorter incubation times and ent ailing a rigorous kinetic methodology, allowed access to apparent kine tic parameters (denoted K'm and V'max). After a hydration of pulverize d materials, the classification according to catalytic efficiency was the same as that based on the percentage of HGB, except for the paraff in-waxed paper. Far the latter, the catalytic efficiency was as high a s that on the filter paper.