Applications of Chitosan, an Eco-Friendly Biopolymer in Agricultural Systems, Herbal Products, and Functional Foods: A Review.

Chitin, the natural biopolymer of the world next to cellulose, is a modified biodegradable polysaccharide. Chitosan, as the major derivative of chitin, is the product of N-deacetylated chitin. Chitosan is an important biopolymer in nature and the only positively charged (cationic) polysaccharide. Chitosan has many utilizations in sustainable agriculture and food systems, in particular, improving plant resistance to environmental stresses like water deficit, salt, high temperature, cold, heavy metal, etc., as well as biotic stresses such as pest and plant pathogens. In addition, this natural biopolymer is used in different industries such as paper, food (processing, packaging, and preservation), pharmaceuticals, biodiesel, and other uses like wastewater treatment and environmental protection. Chitosan gained significant interest for its safety, antifungal, antibacterial, biodegradability, biocompatibility, and antioxidant activities due to its rich amino and hydroxyl groups. The commercial value of chitosan is due to the valuable properties of its soluble derivatives, which are suitable in food processing, cosmetics, nano and biotechnology, environmental, and textile production. In this review, we will consider the effectiveness of chitosan in the performance of agriculture, herbal products, nutraceuticals, and food systems, like improving biologically active compounds in herbal plants as elicitor; the characteristics of chitosan and chitosan-based biopolymers have been mentioned.