Urea degradation in some white wines by immobilized acid urease in a stirred bioreactor.
A purified acid urease preparation was covalently immobilized onto either Eupergit C 250 L or glutaraldehyde-cross-linked chitosan-derivative beads (i.e., Chitopearls BCW-3003 and BCW-3010). The kinetics of urea degradation in two target Italian white (i.e., Grechetto and Sauvignon Blanc) wines, as well as in a model wine solution, by using the above Eupergit C 250 L-, BCW-3003-, or BCW-3010-based biocatalysts, was confirmed to be of the pseudofirst order with respect to the urea concentration in the liquid bulk and not limited by urea mass transfer. In Grechetto and Sauvignon Blanc wines, the corresponding kinetic rate constants were quite similar, being about 7, 18, or 17% of that observed for free enzyme in the model wine solution, respectively. Owing to their minor sensitivity to the phenolic content of the wines tested, the chitosan-based biocatalysts might be potentially employable in the make up of packed-bed cartridges to continuously remove urea from commercial wines.
Andrich
Lucia
L
Department of Food Science and Technology, University of Tuscia, Via San Camillo de Lellis, 01100 Viterbo, Italy.
Esti
Marco
M
Moresi
Mauro
M
D001426:Bacterial Proteins / Q000737:chemistry*; D019149:Bioreactors; D004800:Enzymes, Immobilized / Q000737:chemistry*; D007700:Kinetics; D052197:Limosilactobacillus fermentum / Q000201:enzymology; D014508:Urea / Q000737:chemistry*; D014510:Urease / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D014508:Urea; D014510:Urease