Method for preparing low-molecular weight chitosan by using impulse electric field

Abstract

The invention discloses a method for preparing low-molecular weight chitosan by utilizing pulsed electric field. The method takes high-molecular weight chitosan with molecular weight more than 2.5*10<5>g / mol as the raw material and utilizes pulsed electric field to prepare low-molecular weight chitosan with low-molecular weight less than 2.3*10<4>g / mol. The method comprises the following steps: high-molecular weight chitosan dissolution, pulsed electric field treatment, lye pH adjustment, sedimentation, centrifugation, abstersion and drying, thus obtaining the low-molecular weight chitosan. The pulsed electric field treatment is to treat chitosan solution in a pulsed electric field processor; the electric field strength is 40 to 60kV / cm, the pulse width is 10 to 100mus, the pulse frequency is 100 to 1,000Hz, the pulse waveform is square wave and the period for treating chitosan in the pulsed electric field is 1 to 1,000ms. The preparation method provided by the invention has the advantages of simplicity and feasibility, short electric field treatment period, strong practicality, energy saving and environment protection and easy popularization.

Description

Technical field [0001] The invention relates to a method for preparing low molecular weight chitosan, in particular to a method for preparing low molecular weight chitosan by adopting high-strength pulsed electric field treatment. Background technique [0002] Chitosan is the product of partial or complete deacetylation of chitin, and its molecular chain consists of β-(1-4)-2-acetamido-D-glucose units and β-(1-4)-2-amino -Copolymer composed of D-glucose units. The chitosan molecule contains active amino groups, which can be positively charged and is the only natural alkaline polysaccharide. There are active hydroxyl groups on the sugar ring, so chitosan has good hydrophilicity and water retention. [0003] Chitosan has a variety of biologically active functions such as antibacterial, lowering cholesterol, lowering blood lipids, enhancing immune function, and anti-tumor function. It is widely used in food, biology, medicine, agriculture, environment, materials and other industries...

AI Technical Summary

Problems solved by technology

[0005] 1) Irradiation degradation requires high equipment and may produce toxic and harmful substances.

[0006] 2) The preparation of low molecular weight chitosan by microwave radiation is a batch operation, which is not conducive to continuous production

[0007] 3) The chemical degradation method has many disadvantages such as high cost, low output, and the need to deal with the acid residue;

[0008] 4) The enzymatic degradation method also has problems such as the high cost of the enzyme used for degradation, the complexity of the fermentation process, and the impossibility of mass industrial production.

But these patented technologies are not related to the method of preparing low molecular weight chitosan by using strong pulsed electric field treatment