A review on the preparation and characterization of chitosan-clay nanocomposite films and coatings for food packaging applications

Chitosan, obtained by deacetylation of chitin, is widely available, biocompatible and biodegradable polysaccharide. In the same way, nanoclays have been reported to be abundant, low-toxic, and low-cost, which could be obtained either naturally or synthetically. Due to excellent film forming property, chitosan has been extensively employed in preservation and packaging of foods. However, the opportunity to combine with nanoclays paves the way for enhancing many functionalities (i.e., mechanical, barrier and antioxidant properties) of chitosan-based films and coatings via integration of structural and physicochemical features from both organic and inorganic materials. Moreover, chitosan-clay nanocomposites are easy to fabricate and could be used as carriers for essential oils, metal and metal oxide. In the current review, we first provide an overview of fabrication methods that are specifically applied for the preparation of chitosan-clay nanocomposite films and coatings, and then summarize the advances made in the most recent five years for their food packaging applications.