Chitosan oligosaccharid is a widely used chemical widely used in agriculture, food, chemical, energy, environmental protection, medicine, etc. In this article, I will introduce you to the manufacturing method of Chitosan oligosaccharid, including chemical manufacturing methods and physics. Production method.
Chemical manufacturing method
Chemical methods for degrading chitosan include acid hydrolysis, oxidative degradation, and sodium borate degradation.
Acidolysis: Acid depolymerization of chitosan is one of the most basic and simple methods. It utilizes the characteristics that many free amino groups in the chitosan molecule can bind to hydrogen ions in the solution, causing hydrogen bond cleavage between the molecules of the chitosan and the inside of the molecule, so that the molecular structure is stretched, and the long-chain part is prone to sugary The bond breaks and forms a number of molecular fragments of varying degrees of polymerization.
It is generally hydrolyzed by concentrated hydrochloric acid. Because of its high monosaccharide content, the shell oligosaccharide content is low, a large amount of hydrochloric acid is consumed, the reaction conditions are harsh, a large amount of ion exchange resin is required, the process is cumbersome, the post-treatment is troublesome, and the process is easy to give the environment. It is a huge pressure, so it is not ideal. The chitosan oligosaccharide product prepared by the acetic acid method has the advantages of long-term preservation, and is particularly suitable for the production of food and cosmetic oligosaccharides. In addition, inorganic acids and organic acids such as concentrated sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, trioxyacetic acid and formic acid can also be used to degrade chitin.
Oxidative degradation method: Oxidative degradation method is a method of chitosan degradation in recent years. The oxidative degradation of hydrogen peroxide (H202) has attracted much attention due to its low cost, relatively fast degradation rate, low molecular weight and narrow distribution, no residual toxicity, and easy industrialization. Other oxidative degradation methods include ultraviolet radiation (UV)/H202, NaCl/H202, and the like.
Sodium borate degradation method: It is reported that the preparation process of the method is simple, and the obtained chitooligosaccharide is not only soluble in water, but also has good solubility in organic solvents such as dimethylacetamide and dimethyl hydrazine.
Chemical synthesis: Chemical synthesis can be used to synthesize oligosaccharides with special structures by carefully designing the matrix. The advantage of this method is that oligosaccharides can be designed according to their own needs.
Physical manufacturing method
Ultrasonic and microwave methods: This method can reduce energy consumption, reduce pollution, save time and raw materials, and has industrial prospects and broad market potential.
Radiation degradation under gamma ray irradiation: Radiation degradation is a physical effect of ionizing or exciting chitosan molecules under irradiation of radioactive rays, which leads to molecular chain rupture.
Photodegradation method: ultraviolet, visible and infrared radiation can also degrade chitosan. When the wavelength of irradiation is less than 360 nm, the degradation reaction is obvious.
Enzymatic degradation method: Compared with other degradation methods, the enzymatic degradation method has mild reaction conditions, and the degradation process and the relative molecular weight distribution of the degradation products are easily controlled. The prepared oligomeric chitosan has high biological activity, and the product does not need to be desalted, and the process is easy to control. It does not pollute the environment and is an ideal degradation method.
Glycosyl transfer method: The glycosyl transfer method is based on the enzymatic reaction, and the low-polymerization oligosaccharide is used to extend the sugar chain into a high-polymerization oligosaccharide under the action of the enzyme.
Compound degradation method: Single degradation method has its own advantages, but there are various problems. The emergence of the composite degradation method has made the preparation of oligo-chitosan into a new stage. It is optimized by combining the advantages and disadvantages of various single degradation methods, or introducing newer separation techniques to achieve industrial production.
Whether it is a chemical manufacturing method or a physical manufacturing method, different methods have different advantages or disadvantages. Therefore, in industrial production, different methods should be used for different purposes or environments.