Carbohydrate microcapsules tailored and grafted for covalent immobilization of glucose isomerase for pharmaceutical and food industries

Carrageenan is one of the most common carbohydrates utilised in the entrapment industry to immobilise cells and enzymes. However, it lacks functionality. Carrageenan has been grafted to produce fructose by covalently immobilising glucose isomerase (GI). Fructose is one of the most widely used sweeteners in beverages, food production, and the pharmaceutical business. Up to 91.1 U g(-1) gel beads are immobilised by the grafted beads. Immobilized GI has a V-max of 13.8 times that of the free enzyme. pH of immobilized GI was improved from 6.5-7 to 6-7.5 that means more stability in wide pH range. Also, optimum temperature was improved and become 65-75 & DEG;C while it was at 70 & DEG;C for free enzyme. The immovability and tolerance of the gel beads immobilised with GI over 15 consecutive cycles were demonstrated in a reusability test, with 88 percent of the enzyme's original activity retained, compared to 60 percent by other authors. These findings are encouraging for high-fructose corn syrup producers.