Chitosan-based hydrogel beads: Preparations, modifications and applications in food and agriculture sectors - A review

Chitosan is produced by deacetylation of chitin, the second-most abundant biopolymer on earth. With three types of reactive functional groups, one amino group and both primary and secondary hydroxyl groups, chitosan has been used as a popular biomaterial for synthesis of three-dimensional and flexible hydrogel beads that swell inwater and biological fluids. Chitosan-based hydrogel beads have been found in a wide range of applications in food and agriculture sectors. This review first provides an overview of traditionally used and recently developed methods for preparation and modification of chitosan-based hydrogel beads, and then discusses the advances in the most recent five years in their applications for delivery of food bioactive compounds and treatment of agricultural recycled wastewater. (C) 2020 Elsevier B.V. All rights reserved.