Functional Chitosan-Based Composites for Potential Application in Food Industry

Abstract

Chitosan is a linear semi-crystalline polysaccharide prepared by purification and deacetylation of chitin, which shown as Fig. 21.1. Chitin or poly (Β(1-4)-N-acetyl-D-glucosamine) is one of the most abundant polysaccharides from natural sources which can be found in the exoskeleton of crustaceans and insects and in the cell walls of most fungi and some algae (Ma et al. 2017; Muxika et al. 2017). To purify chitin from the shells of crustaceans, the shells are ground, processed with HCl to achieve demineralization and boiled in dilute NaOH to remove proteins (Puvvada et al. 2012; Arbia et al. 2012; Kumari et al. 2015). Deacetylation of chitin is achieved through alkaline treatment at more than 80 °C. The degree of deacetylation is dependent on the reaction condition. Treatment with 12.5 mol/L NaOH at 95 to 100 °C deacetylates chitin within 2 hours, yielding chitosan with a degree of deacetylation of 87 to 90% and an average MW of 160 to 1600 kDa (Puvvada et al. 2012).