Ionizing radiation applied to one step conversion from different sources of chitin

Abstract

Chitosan is a polyssacharide obtained from chitin’s molecule deacetylation which is the main constituent of some fungi species and the exoskeleton of crustaceans, insects and mollusks. Frequently the production of chitosan is from the crab shells and shrimps that are byproducts of the fishing industry, so it is highly dependent on seasonality. Therefore, finding new chitin’s sources become important. The amino groups present in chitosan give important biological properties such as biodegradability and biocompatibility, activity/immunological effects and antibacterial healing. The chitosan deacetylation process is an aggressive reaction since it requires the attack of chitineous substrate in hot and high concentrated alkalis solution by 1 to 17 hours. It is possible to reduce reagent concentration and time using high-energy irradiation (gamma rays and electron beam). The advantages of radiation use in high-energy include: the absence of chemical initiators, the process can be performed at room temperature and there is no need for the use of solvents. In this work, crab shell, shrimps, squid glads and blattaria were used in order to compare the quality of chitosan found in each animal source. After pretreatment, which include the steps of demineralization and deproteinization, the samples were irradiated at a dose of 20 kGy (gammacell) in order to reduce the deacetylation time. The chitosan from the used chitin sources was characterized by FTIR analysis and its degree of deacetylation was determined.