Investigation of Film with β-Galactosidase Designed for Stabilization and Handling in Dry Configuration.

Gelatin-based films with an immobilized enzyme designed for extending the stability of the protein in dry, non-powder configuration with precise dosing attributes were subjected to stress conditions of temperature and relative humidity. β-galactosidase was used as model functional protein. The film configuration preserved the activity of the enzyme under the different storage conditions investigated, which include room temperature under low (ambient) and high (75%) relative humidity, and 36 °C under low (oven) and high relative humidity conditions for a period of 46 days. The influence of the enzyme and plasticizer (glycerol) on the physical and mechanical properties of the films was investigated using DMA (dynamic mechanical analysis). Films containing 5% β-galactosisdase and glycerol concentrations of 14% or greater exhibited greater tensile strength, Young's modulus, and elongation at break than films with equal concentrations of plasticizer but devoid of any enzyme. The surface texture of the films was analyzed using scanning electron microscopy (SEM). β-galactosidase and glycerol have opposite effects on the surface morphology of the films. Increasing concentrations of the enzyme result in rougher film surface, whereas increasing the concentration of glycerol leads to films with denser and smoother surface. The results obtained suggest that the dry film configuration approach can help in facilitating the stabilization, handling, storage, and transportation of functional proteins in a cost effective manner.