title: Encapsulation of lactase (β-galactosidase) into κ-carrageenan-based hydrogel beads: Impact of environmental conditions on enzyme activity.
abstract: Encapsulation of enzymes in hydrogel beads may improve their utilization and activity in foods. In this study, the potential of carrageenan hydrogel beads for encapsulating β-galactosidase was investigated. Hydrogel beads were fabricated by injecting an aqueous solution, containing β-galactosidase (26 U) and carrageenan (1 wt%), into a hardening solution (5% potassium chloride). Around 63% of the β-galactosidase was initially encapsulated in the hydrogel beads. Encapsulated β-galactosidase had a higher activity than that of the free enzyme over a range of pH and thermal conditions, which was attributed to the stabilization of the enzyme structure by K(+) ions within the carrageenan beads. Release of the enzyme from the beads was observed during storage in aqueous solutions, which was attributed to the relatively large pore size of the hydrogel matrix. Our results suggest that carrageenan hydrogel beads may be useful encapsulation systems, but further work is needed to inhibit enzyme leakage.
authors.affiliation: Department of Food Science, University of Massachusetts Amherst, Amherst, MA 01003, USA.
authors.forename: Zipei
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Food Science, University of Massachusetts Amherst, Amherst, MA 01003, USA.
authors.forename: Ruojie
authors.initials: R
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 213122, China.
authors.forename: Long
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Food Science, University of Massachusetts Amherst, Amherst, MA 01003, USA; Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia. Electronic address: mcclements@foodsci.umass.edu.
authors.forename: David Julian
authors.initials: DJ
authors.lastname: McClements
mesh_terms: D002351:Carrageenan / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D043322:Lactase / Q000737:chemistry*; D001616:beta-Galactosidase / Q000737:chemistry*
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D002351:Carrageenan; D043322:Lactase; D001616:beta-Galactosidase
keywords: Carrageenan; Encapsulation; Enzyme activity; Hydrogel beads; Microgels