title: Immobilization and controlled release of β-galactosidase from chitosan-grafted hydrogels.
abstract: Chitosan-grafted hydrogels were employed for immobilization and controlled released of β-galactosidase. These hydrogels containing immobilized enzymes were employed to simulate the production of lactose-free food and controlled release of β-galactosidase into lactose-intolerant individuals. The degree of swelling, efficiency of immobilization (i.e., fractional uptake of enzyme), and controlled release were studied as a function of pH and temperature. The degrees of swelling decreased in acidic media: 49.4 g absorbed water per g hydrogel at pH 7.0, and 8.4 g absorbed water per g hydrogel at pH 3.5. The immobilization efficiency was 19%, indicating that chitosan-grafted hydrogels are promising matrices for enzyme adsorption and immobilization. Cyclic experiments reveal that chitosan-grafted hydrogels containing immobilized enzymes can be reused several times without introducing additional enzyme prior to each cycle. There is no significant decrease in the activity of the immobilized enzyme during reutilization studies. All results were conducted in triplicate by considering t-tests at a 95% significance level. Analysis of β-galactosidase activity and controlled release reveals that chitosan-grafted hydrogels containing immobilized enzymes are useful for the production of lactose-free food and controlled enzyme release with high performance.
authors.affiliation: Department of Food Engineering, Higher Education Center of the West, Santa Catarina State University, Chapecó/Pinhalzinho, SC 89870-000, Brazil.
authors.forename: Bruno R
authors.initials: BR
authors.lastname: Facin
authors.affiliation: Department of Food Engineering, Higher Education Center of the West, Santa Catarina State University, Chapecó/Pinhalzinho, SC 89870-000, Brazil.
authors.forename: Bruna
authors.initials: B
authors.lastname: Moret
authors.affiliation: Department of Food Engineering, Higher Education Center of the West, Santa Catarina State University, Chapecó/Pinhalzinho, SC 89870-000, Brazil.
authors.forename: Dilmar
authors.initials: D
authors.lastname: Baretta
authors.affiliation: Department of Chemical & Biological Engineering, Polymer Physics & Engineering Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Laurence A
authors.initials: LA
authors.lastname: Belfiore
authors.affiliation: Department of Food Engineering, Higher Education Center of the West, Santa Catarina State University, Chapecó/Pinhalzinho, SC 89870-000, Brazil; Department of Chemical & Biological Engineering, Polymer Physics & Engineering Laboratory, Colorado State University, Fort Collins, CO 80523, USA. Electronic address: atpaulino10@gmail.com.
authors.forename: Alexandre T
authors.initials: AT
authors.lastname: Paulino
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007785:Lactose / Q000737:chemistry; D001616:beta-Galactosidase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D003692:Delayed-Action Preparations; D004800:Enzymes, Immobilized; D020100:Hydrogels; D048271:Chitosan; D001616:beta-Galactosidase; D007785:Lactose
keywords: Chitosan; Food; Hydrogel; Immobilization; Lactose; β-Galactosidase