| Author | Nguyen Thi Thanh Binh |
| Call Number | AIT Thesis no. BP-01-06 |
| Subject(s) | Chitosan--Storage
|
| 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-01-06 |
| Abstract | In this study, the degradation of chitosan in organic acids has been examined. Two methods
of Capillary Viscometry and Gel Permeation Chromatography (GPC) have been applied to
evaluate the change of intrinsic viscosity and molecular weight of shrimp chitosan with a
degree of deacetylation of 81.5% and 88%DD respectively.
Storage of chitosan in 0.2M acetic acid was examined during 60 days at three different
temperatures: 5, 28 and 60°C. It was found that the higher the storage temperature, the faster
the rate of degradation. The viscosity of 8 l .5%DD chitosan was reduced to less than 10% of
the original value after 60 days of incubation at 60°C. The chitosan of higher degree of
deacetylation has a better resistance to acid hydrolysis. Minor changes on the intrinsic
viscosity and molecular weight were observed after the treatment at 28°C and nearly no
change after treatment at 5°C.
The intrinsic viscosity and molecular weights of chitosan in three concentrations of acetic acid
of 0.1, 0.2 and 0.8M before and after precipitation was compared. No significant difference
has been found. The effect of formic acid and acetic acid in various concentrations on
degradation of chitosan was studied. After incubation the chitosan was precipitated with alkali
and redissolved in acetic acid. It was found that chitosan is more resistant to degradation in
foimic acid than in acetic acid. However, between three concentrations of 0.1, 0.2 and 0.8M
of individual acid, only minor differences in the rate of degradation were observed.
The results in viscosity-average molecular weight obtained from viscometry method were
very consistent with the results in weight-average molecular weight obtained by GPC method.
This illustrates the accuracy of these analytical methods and suggests that viscometry method
can be widely used for determining the molecular weight of chitosan in routine laboratory. |
| Year | 2001 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. BP-01-06 |
| 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.; |
| Examination Committee(s) | Suwalee Chandrkrach;Traenkler, Josef;Suwabun Chirachanchai; |
| Scholarship Donor(s) | Swedish International Development
Cooperation Agency (Sida) ; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2001 |