Optmization of invertase immobilization in Duolite A-568
Special Symposium - Innovations in Food Technology (LMC Congress)
Innovations in Food Technology - Poster Session (Food - P2)
Keywords: inverted sugar, Duolite A568, immobilization, invertase
The inverted sugar is a natural sweetener constituted by the mixture of glucose, fructose and sucrose, obtained from the sucrose hydrolysis. The hydrolysis can be enzymatic, being catalyzed by free and immobilized invertase, resulting in a high quality product with no color development and free of undesirable by-products, thus differing from the acid hydrolysis. This work presents as a main objective to study the immobilization process of invertase by adsorption on ion exchanging resins. It was studied the immobilization process of invertase from yeast in Duolite A568, one weak exchanging anionic resin. The simultaneous influence of pH, temperature and enzyme concentration in the immobilization process was studied by a Central Composite Design (CCD).The results indicated that the retention of the catalytic activity in the immobilization was strongly dependent of these variables, being maximum in a pH value of 5.0, with an enzyme concentration of 12.5g/L at 30 ºC. A Central Composite Design (CCD) was utilized to study the simultaneous influence of temperature and pH in the activity of immobilized invertase and the values of maximum activity was 35ºC and pH of 4.5. The obtained immobilized biocatalyst was highly stable in a pH range from 5.5 to 6.0 and the study of enzyme stability indicated a deactivation energy of 416 kJ/mol. The sucrose hydrolysis by immobilized invertase was inhibited by substrate and reaction products.
