Isolation of chitin and chitosan from crab shells | |
| Author | Khin Than Myint |
| Call Number | AIT Thesis no. BP-00-05 |
| Subject(s) | Chitosan Chitin Biotechnological microorganisms--Isolation |
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. BP-00-05 |
| Abstract | The objective of this study is to develop the laboratory scale technology for the isolation of chitosan from crab shell with high molecular weight. The specific problem is the large amount of minerals in the crab shell. This is mainly due to the high content in calcium carbonate. highest among crustacean shells. The calcium carbonate has to be removed without damaging the polymeric structure of chitin and chitosan. HCl. that is very efficient for the removal of calcium carbonate in particular. is also an etlicient agent to depolymerize the polymer. In general one might expect that the milder the I-IC! treatment. the higher the molecular weight but also the higher the remain ing. mineral content of the product. In th is stud y. the lowest amount of HCI was determined required fllr nearly complete decalcitication. Various HCI treatments have been compared. including double HCI treatment combined with the deproteinization in various seq uences. The total amount of HCI required has been estab lished. Various concentrations of HCI. but with a fixed total amount of HCl have been compared. Deproteinization prior to decalcification is required to reduce efficiently the ash content of chitin in the demineralization step. Chitin with a protein content of< 1 % could be obtained by treatment with 4%NaOH 60°C for 24h. The physio-chemical characteristics of crab chitosan have been characterized by the degree of deacetylation, viscosity and molecular weight. The chitosan quality is affected by the temperature. concentration of alkali and the duration of the deacetylation step but also by the HCl concentration in the preceeding demineralization Aggressive !Zonditions of HCI treatment resulted in less viscosity and molecular weight of the chitosan. |
| Year | 2000 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. BP-00-05 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Bioprocess Technology (BP) |
| Chairperson(s) | Stevens, Willem F.;Suwalee Chandrkrachang; |
| Examination Committee(s) | Rakshit, Sudip K;Pakom Nuchnoi; |
| Scholarship Donor(s) | Asian Institute of Technology; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2000 |