The Extraction And Composition Of Polysaccharides And Properties Of Dietary Fiber From The Roots Of Flammulina Velutipes Mycorhiza

The roots of Flammulina velutipes mycorhiza were used as experimental materials for extracting polysaccharides with hot water and ultrasound-associated methods. The obtained crude polysaccharides were then purified into FMP-1and FMP-2for further characteristic analyzing. The contents and quality of dietary fibers in root residue of Flammulina velutipes mycorhiza after polysaccharides extraction was determined and evaluated. The main results were shown as following:1. The each method of hot water and ultrasound-associated extraction were use to extract the polysaccharides from the roots of Flammulina velutipes mycorhiza and then optimized by orthogonal experiments on the basis of single factor test. The results show that the optimized condition for extracting polysaccharides with hot water method was: liquid-solid ratio30:1at90℃for3.5h, and polysaccharide content was up to7.89%. The optimized condition for extracting polysaccharides with ultrasound-associated extraction was:liquid-solid ratio35:1at80℃with ultrasonic power180W for40min, and the obtained polysaccharide was7.69%.2. The effectiveness of protein removal from crude polysaccharides by sevag method and TCA method was investigated based on polysaccharides loss and protein retention. The result showed that TCA method at10%concentration was better than the other. By taking this method,79.05%protein was removd with only4.79%polysaccharide loss,which was much less than that by taking sevag method.3. The crude polysaccharides extracted by ultrasound-associated method was applied into DEAE Cellulose-52and Sephadex G-100chromatography and two purified fractions of FMP-1and FMP-2were obtained. The characteristic analyses of crude FMP, FMP-1and FMP-2showed that contents of polysaccharides were85.12%,98.70%and96.53%, and proteins5.24%, not detected and2.16%, and uronic acids12.61%,14.29%and14.01%, and sulfuric radicals1.28%,0.58%and1.52%, respectively. By adopting FT-IR spectrum, the characterized absorption features of polysaccharides, carboxyl group and pyranose ring were observed in FMP-1and FMP-2, and absorption peaks of amino group and sulfuric acid radicals in FMP-2were stronger than that in FMP-1. The above protein testing result was approved by ultraviolet spectrum scanning atlas.FMP-1was mainly composed of glucose, galactose, mannose, fucose and rhamnose with a molar ratio of52.69%,2131%,10.80%,7.54%and1.61%. FMP-2was mainly composed of galactose, glucose, mannose, fucose with a molar ratio of35.91%,26.12%,25.21%and12.76%.4. The composition analysis of the extracted root residues of Flammulina velutipes mycorhiza showed that the IDF content reached up to69.84%, of which was42.55%Cellulose,20.82%hemicellulose and6.20%lignin, only1.40%SDF, and with some moisture, fat, proteins and merials. Within69.84%IDF was. Water holding capacity, expansion force and oil holding rate of the residue and puried dietary fiber were5.51g/g,8.77g/g;3.5ml/g,7.0ml/g;2.28g/g,2.72g/g, respectively, indicating that the extracted root residues of Flammulina velutipes mycorhiza was rich in dietary fibers with high quality, and further purification could significantly improve dietary fiber quality.