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Polysaccharides extraction method introduction

Nov 23, 2020

Polysaccharide is not a pure chemical substance, but a mixture of polymerization substances with different degrees. Generally speaking, Polysaccharides are insoluble in water, have no sweet taste, cannot crystalize, Polysaccharides are also glycosides, so they can be hydrolyzed. In the process of hydrolysis, a successive intermediate products are produced, and finally are completely hydrolyzed to achieve monosaccharidesPolysaccharide struction


1. Solvent extraction for polysaccharide extraction

(1) Water extraction : using water as the solvent, hot water extraction or cold water extraction can be used (plant polysaccharides are mostly extracted with hot water, and impurities can be removed directly or by centrifugation). Since polysaccharides are insoluble in ethanol, they can be removed by precipitation The polysaccharide is purified. The disadvantages of water extraction are high temperature and engergy consumption, time-consuming, and low extraction rate.


(2)Acid extraction : Some polysaccharides containing acidic groups are not easy to dissolve under acidic conditions. After treatment with hydrochloric acid or acetic acid, the polysaccharides are precipitated with ethanol or insoluble complexes. Acid extraction is easy to destroy the spatial structure of polysaccharides and is not widely adatped.


(3) Alkaline extraction: Some polysaccharides and acidic polysaccharides containing uronic acid are relatively stable under alkaline conditions, which can increase the extraction rate of polysaccharides. Generally, sodium borohydride or potassium borohydride is used as a solvent. The disadvantage is that certain polysaccharides will degrade when they are strongly alkaline, and it is easy to affect the color and flavor of the finished product.


2. enzyme extraction

Under certain conditions, enzymes can accelerate the release and extraction of polysaccharide components in the sample. Enzymes can be divided into two types: single enzyme and complex enzyme. Generally, complex enzymes are the most commonly used, such as pectinase, protease, cellulase, etc. The enzyme extraction has the characteristics of mild conditions, easy removal of impurities and high recovery rate, and has broad development prospects.


3. Polysaccharide extraction ultrasonic assisted extraction

Ultrasonic-assisted extraction is an efficient and practical polysaccharide extraction . It mainly uses the mechanical effects and cavitation of ultrasonic waves to destroy cell walls, cell membranes and other biological tissues, and increase the mass transfer efficiency within the cells, thereby promoting the release and extraction of plant polysaccharide components . Compared with the traditional extraction , the ultrasonic assisted extraction has higher extraction rate, shorter time and lower energy consumption.

ultrasonic extraction tank


4. Microwave-assisted extraction for polysaccharide extraction

Microwave radiation is used to make the polar substances in the cells get a lot of heat, causing the temperature in the cells to rise. The pressure generated by the vaporization of liquid water causes the cell membrane and cell wall to rupture, forming tiny holes, and the intracellular polysaccharides are released. The microwave-assisted extraction has the advantages of fast heating, strong penetrating power, and short extraction time.


5. Polysaccharide extraction high-pressure pulse extraction

The use of high-voltage short pulses to release polysaccharide components, the mechanism of action has not yet reached a consensus, and the cell membrane perforation effect is the most studied.