Studies On Extraction, Purification,Structure Analysis And Biological Activity Of Polysaccharides In Raspberry Fruit

Raspberry is Rosaceae Rubus plants, bush fruit, which the European and American countries have already widely cultivated, our country from south to north, from west to east have a wild species distribution, it is a favorite of the third generation of fruits. Raspberry tender and juicy, inviting color, unique flavor, it rich in vitamins and mineral elements, especially rich in polysaccharides, fiavonoids, SOD, ellagic acid and other active substances, which is known as the "fruit of life", In this study, raspberry fruit as raw material, The extraction conditions of raspberry polysaccharide were discussed, And further on the polysaccharide were studied in isolation and purification, structure identification and biological activity.And provide the reference basis for the development, development of in-depth study of raspberry polysaccharide health benefits and polysaccharide product.Extract polysaccharides by composite enzyme method, on the basis of single factor by using response surface analysis method, the yield of polysaccharide as the index, three factors of pectinase, cellulase, papain on extraction rate.To determine the optimal enzyme ratio:pectinase:enzyme:papain:=2.5:1.7:2.1, Then the other factors of the experiment of two composite, Determination of compound enzyme optimum reaction conditions:Compound enzyme dosage2.6%, pH4, temperature55"C, extraction time2.6h, test rate reached4.09%, close to thepredicted value.The polysaccharide is insoluble in ethanol, the ethanol waspreliminary purification, According to the final purification effect is determined by95%ethanol purification. Preliminary purification of using macroporous resin on raspberry polysaccharide, Through the static adsorption and desorption kinetics experiment, Select D4020from8kinds of macroporous resins for raspberry polysaccharide purification macroporous resin. Through the D4020of raspberry polysaccharide dynamicadsorption and desorption experiment to get the bestcondition:at20℃, the concentration of sample3mg/mL, adsorption velocity108mL/h, the injection volume2mL, and eluted by deionized water, eluting rate72mL/h, elution volume110mL. Under these conditions the raspberry polysaccharide purity up to52.7%, than the unpurified before the purity of13.73%is nearly4times higher.The preliminary purification of polysaccharide RCP was isolated and purified by Sephadex G-100. eluted with deionized water, two fractions were obtained, RCPI, RCPII. Select the polysaccharides content is high component RCPII enriched, by Sephadex G-100chromatography, HPLC and freeze-thaw test, RCPII is homogeneous components, The molecular weight of3.9×103Da, and the purity is up to92.76%. The purified polysaccharide from RCPII is a solid white floc, solved in hot water, didn’t dissolve in some organicsolvent such as ethanol, aether and acetone, responded negatively to Lane and Eynon’s Method, iodostarch reaction and dye reaction of Coomassie Brilliant Blue G-250; responded positively to penol-sulfuric acid, antnrone-sulfuric acid and sulfuric acid-carbazole chromogenic.The monosaccharide standards and derivatives of RCPII hydrolysate were analyzed by Gas chromatography, and the results showed that RCPII is a heteropolysaccharide, composed of arabinose, glucose, galactose and mannose, its molar ratio of rhamnose:arabinose:xylose:glucose:galactose=1:2.07:0.72:0.85:3.54. Infrared spectroscopy analysis showed that RCPII is a heterosaccharides with pyran and acetyl amino group. By using UV spectrum, it was found that there were no absorption peaks of protein and nucleic acids at280nm and260nm, and no pigment peakat512nm. These show that D4020macroporous resin purifies well. NMR results show that beta glycosidic bond structure containing polysaccharides RCPII, another may contain6deoxy sugar. The other Congo red test show that, polysaccharide extraction does not contain three helical structure.The test of free radical scavenging activity results show that:compared with Vc, raspberry fruit polysaccharide on DPPH·, OH·, O2-·, have certain scavenging effect. RCPII has a very clear role in the removal of DPPH, and the clearance rate is higher than that of Vc control.RCP on OH, O2-, although also has ascavenging effect, but the clearance rate less than Vc control. Non enzymatic glycosylation of protein inhibition test results:RCPII on The initial stage of the reaction products of Amadori formation, the reaction medium two carbonyl compounds and the end product formation reaction of AGEs has certain inhibition.The end product inhibition of AGEs rate reached45.47%, it is higher than that of the initial stage of the reactionto inhibit Amadori production rate of29.61%and reactionmedium28.74%. This indicates that the effect of raspberry fruit polysaccharide on non enzymatic glycosylation reaction mainly occurs in the reaction stage.