Study On Extraction,separation,purification Of Polysaccharide From Bamboo Sawdust

The research of bamboo resources is very active and the development and utilization of bamboo resources, extraction its effective active materials, become the focus of the research at present. Bamboo sawdust, an important part of bamboo,which is considered as waste is worth to discuss no matter if it includes a variety of potential biological activities like bamboo leaves and bamboo shoots or not. In addition to the flavonoid, polysaccharide is one kind of good biological activity of macromolecular material in bamboo, which is widely applied in medical field with its function of antioxidation, antitumor, antivirus, antiulcer, antimutagenic, lipid decreasing,hypoglycemic,etc.Developing the resources of bamboo sawdust polysaccharide,studying the optimum parameters of extraction and purification technology and determining the functions and mechanism of the biological activity will provide theoretical basis of bamboo sawdust polysaccharide for the promotion and application in the industry in the further.In this paper, bamboo sawdust is used as raw material to produce polysaccharide.The processing parameters of hot water, microwave, and ultrasonic wave-assisted extraction technology were all studied, and the best method and process parameters of bamboo sawdust was determined. The characters of the purity polysaccharide deproteinized and decolored were studied.And the studies can provide some suggestions for application and exploration of bamboo and some theory for the functional study of polysaccharide from the bamboo sawdust.The main contents and results are shown as follows:(1)The extraction of polysaccharide from bamboo sawdust. The method of anthrone-sulfuric acid wad used to mensurated of bamboo sawdust polysaccharide.Analyzed the extraction ratio of polysaccharide in bamboo sawdust used hot water,microwave, and ultrasonic wave-assisted extraction technology to extractpolysaccharides.The using water optimum extraction conditions were as follows :solid-to-liquid ratio was 1:15 at 85℃ about 2.5h.The extract rate of polysaccharide is2.278mg·g-1 based on the above mentioned.The ultrasonic wave extraction optimum condition were: material-liquid ratio was 1:20, 30 min, ultrasonic extraction power60%, 65℃.In this condition, the extraction rate of polysaccharide was1.484mg·g-1.The microwave extraction optimum condition were:solid-to-liquid ratio was 1:12, 8min, extraction power700 W,Under the optimized condition, the extraction rate of polysaccharide was 2.026mg·g-1.The result shows that although microwave assisted extraction and ultrasonic extraction shorten the extraction time, but the difficulty of the subsequent filtering processing has increased, and the total yield compared to the hot water extraction was only slightly lower, so this paper selects the hot water extraction for the extracting polysaccharide from bamboo sawdust.(2) The separation, purification of polysaccharide from bamboo sawdust. Process of removing protein and decolorization were studied and optimized.Trichloroacetic acid, papain and combination of TAC and papain were used for deproteinization. The results showed that the combination of TAC and papain method has the best effect.The deproteinization rate was 96.706% and polysaccharide retention was95.480%.Process of decolorization:Contrasting three decolorization methods such as hydrogen peroxide oxidation method,activated carbon attaching method and resin AB-8 method, After incorporating the decoloring rate and polysaccharide retention rate, the resin AB-8 method is best.By the means of single factor and orthogonal test,we can get the best parameters as follows: temperature was 35℃, time was 1h,pH was 5.5, and the dosage was 9g.In this condition,the decolored ratio was 86.150%,polysaccharide retention was 94.400%.(3) The physical and chemical properties and structure analysis of polysaccharide from bamboo sawdust.The purified polysaccharide of bamboo sawdust was analyzed by physical and chemical properties and infrared spectrometry, the results indicate that it was non-starch polysaccharide without protein or polyphenol material, but it contains uronic acid.The ultraviolet spectra results showed that bamboo sawdust polysaccharide did not contain nucleic acid or protein. By IR analysis it wasconcluded that the sugar units maybe connected by α-pyranose bond.(4) The anti-oxidant activity of bamboo sawdust polysaccharide. The capacity of bamboo sawdust polysaccharide on scavenging hydroxyl radical(·OH), superoxide anion radical(O2-·), and 1,1-diphenyl-2-picrylhydrazyl radical(DPPH·) etc, were studied in vitro.The result showed that bamboo sawdust polysaccharide have a certain capacity on scavenging·OH, and DPPH·; and the efficiency of scavenging is increased by the concentrations.The results show that bamboo sawdust polysaccharide has the anti-oxidant activity.