Chitosan is a linear polysaccharide composed of randomly distributed β-(1→4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit) . It is produced commercially by deacetylation of chitin, which is the structural element in the exoskeleton of crustaceans (such as crabs and shrimp) and cell walls of fungi. The degree of deacetylation (%DD) in commercial chitosans ranges from 60 to 100%, and the molecular weight of commercially produced chitosan is 3800–20,000 daltons.
Chitosan has several positive properties, including good antibacterial, antioxidant, and antimicrobial properties. It is also used in food packaging due to its ability to reduce the growth of microorganisms and extend the shelf life of food products. Additionally, chitosan has been used in medicine and drug manufacturing, as it can help blood clot when applied to wounds and might reduce how much fat and cholesterol the body absorbs from foods.
However, chitosan also has some negative properties. It has low mechanical strength and low-temperature response rate, and it must be combined with other gelling agents to improve its properties. Moreover, there is no good scientific evidence to support many of the uses of chitosan, such as for high blood pressure, high cholesterol, obesity, and wound healing.
In terms of ingredients or materials, chitosan is a sugar that comes from the outer skeleton of shellfish, including crab, lobster, and shrimp. It has a positive chemical charge, which causes it to attract negatively charged materials.
