Chitin and Chitosan
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Researcher
Dr.Piyabutr Wanichpongpan
Department of Chemical Engineering, Faculty of Engineering
Tel. 0-2470-9007 Fax. 0-2428-3534
Rationale
Chitin falls in the category of carbohydrate with fiber structure similar to that of cellulose of plants. Chitin is found in the shell of animals like shrimp, crabs, squid pen, insects, silk worms, pearl shells, and the cell walls of fungi, yeast and many other kinds of microbes. There are three different types of strong crystal structure of chitin in nature, namely alpha chitin found in the shell of crustaceans such as shrimps and crabs, beta chitin found in squid pen or shell, and gamma chitin format in insects and fungi.
Chitosan (deacetylated chitin) is a biopolymer extracted from chitin, which is the main structural component of the shells of crustacean shells, squid pens and the cell walls of some fungi. Chitin and Chitosan are copolymers found together in nature. The quantity of chitin is second to cellulose. Chitin and Chitosan has an inherent property of being environmentally friendly and easily degradable. They especially have amino groups, which possess many properties different from cellulose such as solubility in dilute organic acid, effective capability of binding with metal ions and its biological effect. Nowadays, Chitin and Chitosan are used in the industrial, agricultural, medical and pharmaceutical sectors. They are used as flocculant in factories' wastewater treatment, in textile industry to prevent bacteria and fungi, in dietary supplements for their quality of reducing fat and chloresterol, in products for beauty, which is of interest to women, as growth enhancer for plants and meat-yielding animals such as pigs, shrimp, ducks, chickens, as fruit coating to prolong conserving period, as preservative and as wound coating film to accelerate the wound healing process.
With regard to the overview of Chitin-Chitosan application in Thailand today, it can be said that Thailand enjoys an advantage to other countries since it has plenty of raw materials (shrimp and crab shells). This advantage in relation to raw materials is due to the fact that Thailand is a world-leading exporter of frozen shrimps. Although the government has a policy to cut down shrimp farming areas, since shrimp shells, which are the raw materials in the production of Chitin and chitosan, are obtained from two sources namely shrimp farms, with approximately 200,000 tons a year, and from the sea, with approximately 300,000 tons a year, there should not be any problem of raw material shortage when there is greater demand of Chitin-Chitosan in the market. Besides, Thailand is prepared in terms of technology. The technology required for the production of Chitin and Chitosan is not complicated. It can be done in households, communities or in industrial factories. At present there are a small number of factories producing Chitin-Chitosan. Their production capacity is not very high and they are not very well known. If the market demand increases, the expansion of the production to an industrial level is possible and can be done rapidly since it does require much investment, machinery or labor. The production system can be easily managed due to the preparedness in many aspects as mentioned above. In the future, Thailand can be a world-leading exporter of Chitin-Chitosan as it is of frozen shrimp. With regard to the production process using chemicals, which may give rise to issues such as environmental problems and chemical contaminants, these issues can be resolved and controlled by applying the knowledge of clean technology and biotechnology. In addition, we can develop the production to cover a wide range of products: from Chitin and Chitosan to products made with Chitin-Chitosan such as fertilizers, cosmetics, dietary supplements, etc., which is a way to create an added value to the material. Moreover, there will not be a foreign trade deficit in this respect. That is to say if we export Chitin and Chitosan to foreign countries such as Taiwan and Japan, those countries then make products from these raw materials and sell them to Thailand at prices much higher than the prices of Chitin-Chitosan we have sold to them. Thai scientists and researchers in Thailand can indeed develop those products. Nevertheless, they still need support and production promotion as well as cooperation among scientists, researchers, industrial people and entrepreneurs in order to have a complete range of products in the future.
Properties and features
*Property and Function **Application and Developed Products
1. Polyelectrolyte and chelate (B)
  1. Coagulant and flocculant and cationic agent for wastewater treatment
  2. acidic protein flocculant and flocculant to separate uranium and certain kinds of metals as well as radioactive metals
2. Forming different shapes (A, B)
  1. 1. To form fiber and textile
  2. To form a thin film used in filtering separation as in separating water from alcohol
  3. 3. To form a pellet or capsule for cell culture
3. Absorbing gel (B)
  1. Cell membrane and enzyme membrane
  2. To be a medium for gel chromatography separation
  3. To form a porous sponge-like shape
  4. Cherogel
4. Carbon dioxide immobilization (A, B)
  1. To immobilize carbon dioxide in the atmosphere
  2. To be a combining substance with carbon dioxide
5. Water degradability (A, B)
  1. Production of glucosamine and oligomer of sugar (by chemical and enzyme)
6. Viscosity and water holding (B)
  1. An ingredient in cosmetics, for skin and hair products
7. Molecule absorbency (A, B, C)
  1. Used as a medium in different kinds of chromatography e.g. absorbent and exchange to separate lectin, chitinase and lysozyme
8. Chemical reaction (A, B)
  1. To create odor and taste
  2. To remove the smell of formaldehyde
  3. Synthesis of derivatives as spin-offs
9. Conductance (B)
  1. A thin layer of chitosan combine with lithium and triflate used as environmentally friendly electrolyte in battery
10. Enameling (B)
  1. Coloring in printing, dying and additives
  2. Paints
  3. Speakers and musical instruments
  4. Additives in paper industry
  5. Fruit and vegetable coating, to prolong conserving period
  6. Seed coating
11. Extractor (A, B, C)
  1. Inductor of potentially harmful proteins
  2. Agricultural agents e.g. seed coating, leaf coating
12. Anti-microbial (B) Used in fruit and food preservation
13. Promotion of useful microbes (A, B) Help improve useful microbes such as
1. those in earth and water
2. those in animals and human beings
14. Non-toxic Being environmentally friendly, it can be used for any purposes.
15. Create immune system (A, B, C)
  1. Induce lysozyme and LPL activities in tissues and blood
  2. Anti-cancer agent
16. Wound healing (A, B, C)
  1. Used to especially burns and skin wounds in human beings, animals and plants (preparation of artificial skin)
  2. Heal bones, ligaments and repair ligaments of organs
17. Biodegradability (A, B, C)
  1. Biodegradable suture
  2. 2. Controlled release of drugs
  3. 3. Enzyme immobilization
18. Chloresterol reduction (B)
  1. Used in dietary supplements and additives in animal feeds
  2. Lower blood pressure
19. Hemostatic property anti-thrombosis (C)
  1. Hemostatic agent
  2. Used to make artificial blood vessels and contact lens
20. Used as film for fruit coating (B)
  1. Help keep fruit and vegetable fresh for longer period
21. Compatibility with human organs
(A, B, C)
  1. Wound healing
  2. Suture
Remarks   * A is chitin. B is chitosan. C is derivative of chitin and chitosan.
                 ** The underlined are products now available in the market.
Applications
I have conducted research in Chitin-Chitosan and have personally made applications of Chitin-Chitosan as I have a small farm not far from Bangkok where I have pigs, ducks, chickens raised and fruit planted e.g. papaya, lime, mango etc. When Chitin-Chitosan extracts were used on these animals and plants, we obtained very satisfactory quality of yields. In addition, Chitin and Chitosan have been used in rice fields and flowers and decorative plants in the mountains in northern Thailand. The application of Chitin-Chitosan will lead to organic farming, which will help mitigate environmental problems and the problems of chemical contaminants. It is safe to both farmers as users and to consumers of agricultural products and can substitute use of chemicals, which mostly have to be imported from abroad.

  update : 13 August 2002