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Comparison of Kinetic Profile of Free and Immobilized Glucose Oxidase, Immobilized on Low-Density Polyethylene Using UV Polymerization

Kothapalli, A., Hayes, K., Sadler, G., Morgan, M.
Journal of food science 2007 v.72 no.9 pp. C478
food packaging, food contact surfaces, glucose oxidase, immobilized enzymes, polyethylene, ultraviolet radiation, polymerization, enzyme activity, enzyme kinetics, fruit juices, antioxidant activity, ambient temperature, storage temperature, refrigeration, shelf life
Bioactive packaging is an important area of active packaging in which an active component is incorporated into the food contact surface of the package to interact with the food components without itself migrating into the food. Embedding bioactivity in a UV polymerizable resin is a novel and versatile technique for incorporating bioactive components into food packaging. In a previous article, glucose oxidase was immobilized in a packaging material using a UV curable resin. The relevance of this model system for deoxygenation of fruit juices was discussed. Though the technique efficiently immobilized enzymes in packaging material, during polymerization and immobilization the catalytic ability of the enzyme was not specifically explored. This article compares and contrasts the catalytic ability in terms of the kinetic profile of free and immobilized enzyme for the same model system: deoxygenation of juices. Kinetic behavior of immobilized and free glucose oxidase enzyme was evaluated at both shelf stable (room temperature) and refrigerated storage conditions to simulate the actual package life. It was observed that both the free enzyme and the immobilized enzymes follow the Michaelis-Menten kinetics model. There was no significant difference between the catalytic ability (kcat/Km) of free and immobilized enzymes at treatment temperatures (30, 25, and 10 °C); however, at refrigeration temperature (5 °C), the values for free enzyme were significantly higher than the immobilized enzyme.