Effect of pigment volume concentration on the enzyme activity of bioactive coatings

Abstract:

The aim of this project was to study the effect of pigment volume concentration on enzyme activity by using two different kinds of pigments (kaolin clay and calcium carbonate) in various concentrations. The coating colors were coated on various kinds of substrates for the different methods including flexible paper, board and plastic film. All coating colors contained a latex of standard grade, starch, pigment and the chemical compound used by enzyme, in this case β-D-glucose. The paper substrate used was a white top kraft liner with a grammage of 140 g/m², while the board had a grammage of 244 g/m². The plastic film used was a standard Mylar film. All coating colors with various amounts of the two pigments (without enzyme) were coated on the paper and board substrates. The resulting coat weight and the thermal conductivity were measured. The Cobb-Unger oil absorbency was evaluated using double coated plastic sheets for different pigment volume concentrations of the two pigments. The oxygen scavenging ability of the enzyme in the various coating colors coated on the barrier board was also evaluated. For the determination of enzyme activity, glucose oxidase, catalase and glucose were added to latex dispersions in the preparation of the coating colors. The enzymes were entrapped in the coating layers after coating and drying. The activity of enzyme incorporated in the coating dispersions was compared for the two different pigments. The results indicated that the pigment concentration had a significant effect on the enzyme activity.