Computerized enzymatic kinetic method for glucose determination in foodstuff using immobilized glucose oxidase in gel beads

A new reliable semi-automatic procedure for enzyme immobilization in uniform calcium alginate beads is introduced, and a simple, low-cost measuring kinetic technique for enzymatic analysis is presented. Immobilized glucose oxidase, in calcium alginate beads, was used to catalyze the glucose oxidation reaction. The reaction was monitored photometrically at 460nm, by means of an indicator reaction based on the oxidation of o-dianisidine by hydrogen peroxide, in the presence of peroxidase. Under optimum conditions, the enzyme-gel beads show a good behaviour for at least two months and for at least 20 consecutive measurements on the same sample. The method was applied to the determination of glucose in foodstuffs like honey, artificial beverages, ice-cream toppings, and the results were compared with those obtained by two standard methods.