Chitin is an important polymer found in crustacean shells. Conversion of chitin can lead to chitosan, which can be used as a gelling agent for developing physical hydrogels. In this PhD, chitosan gels are developed for the encapsulation and delivery of sensitive natural bioactive compounds, such as phenolic compounds and carotenoids. Other properties of chitosan (e.g. flocculant and antioxidant agent) are also investigated.