India Blocks Separated And Purified Polysaccharide, Characterization And Antioxidant Research

Yunnan province has rich resources of truffles, the truffles of Yunnan is Tuber indicum, which has the similar nutrition and function with black truffle, is a kind of highly nutritional value and commercial value of edible fungi. People have pay more and more attention to the polysaccharide from truffle, because of its special biological activity such as antioxidant, anti-older, antitumor, antivirus, and has a great application prospect in food, health care products and medicine. At present the truffle in Yunnan province is mainly eaten by fresh, but the study of the deep processing and extraction of functional components to use have no people to do. So far most of the research of truffle at home and abroad is limited to the aromatic nature, mycology and artificial culture and so on, the research of truffle polysaccharide has very few reports, the differences of regional can make a large difference of material, therefore, it is necessary to begin the research of polysaccharide from India truffle of Yunnan production. In this paper, the condition of water extraction of polysaccharide from India truffle of Yunnan production is optimized, crude polysaccharide is purified and the structure is preliminary deduced,the antioxidant of polysaccharide is tested, makes every effort for the future truffle product development to provide reference. The main research contents and results are as follows:1. Process optimization of water extraction of polysaccharide from India truffleThe study of extraction process of polysaccharide from India truffle is through the water extraction and alcohol sink method, and the optimization of extraction technique was carried out by the response surface method. The results show that the best process conditions of polysaccharide from India truffle through water extraction aer extraction time is3.71h, extraction temperature is95℃, Water-feed ratio is59:1(mL:g), in this condition the extraction ratio of polysaccharide from India truffle is10.8%.The order of influence to polysaccharide extraction ratio is extraction temperature>extraction time>Water-feed.2. Separation and purification of polysaccharide from India truffleThe crude polysaccharide from India truffle extracted through water extraction is taken off the protein through Sevage method.The crude polysaccharide get through the DEAE cellulose column chromatography under the ultrapure water,0.3mol/LNaC1,0.5mol/LNaCl,get three components:PTI-1,PTI-2,PTI-3. The PTI-2, through the Sephadex G-100glucan gel column chromatography, get a single componennts PTI-2A, test the purity by HPLC and gel column, the result shows that PTI-2A is a pure polysaccharide.3. Physicochemical property and deduce of structure of PTI-2AAfter lyophilization PTI-2A is amorphous flocculent gray solid, soluble in water, dilute acid, dilute acid, not soluble in methanol, acetone, chloroform, diethyl ether and dimethyl sulfoxide organic solvent, PTI-2A does not contain protein, nucleic acid, phenols, amylum and free monosaccharide. Uronic acid contain of PTI-2A is9.94%.The molecular weight of PTI-2A is193388.2Dal tested by HPLC, the monosaccharide composition of PTI-2A is only comprised by glucose tested by GC. PTI-2A does not contain protein, nucleic acid, pigment tested by UV spectrum, it was presumed the structure of PTI-2A is α-D-glucopyranose units joined by a-D-1→6glucosidic bond tested by IR spectrum and nuclear magnetic resonance (NMR).4. In vitro antioxidant test of crude polysaccharide and PTI-2AEvaluation of antioxidant activity of crude polysaccharide from India truffle and PTI-2A are measured by the methods of DPPH radical scavenging activity, hydroxyl radical scavenging activity and reducing power.The results indicate that crude polysaccharide from India truffle and PTI-2A both have good antioxidant activity of DPPH radical scavenging activity and hydroxyl radical scavenging activity, but the reducing power is weak. The EC50of crude polysaccharide from India truffle of DPPH radical scavenging activity, hydroxyl radical scavenging activity and reducing power are respectively1.12mg/mL、0.73mg/mL、2.06mg/mL. The EC50of PTI-2A of DPPH radical scavenging activity, hydroxyl radical scavenging activity and reducing power are respectively0.6mg/mL、0.35mg/mL、1.05mg/mL, are stronger than crude polysaccharide. The antioxidant activity is concentration dependence, become stronge with the rising of the concentrations.