Study On Microwave-assisted Enzyme Extraction And Properties Of Polysaccharide From Shaddock Peel

The shaddock has a rich variety and large yield in China.But the study of shaddock flesh is more than that of shaddock peel.The intensive study of shaddock peel is not enough at the present.Every year,a large number of shaddock peel not only pollute the environment,but also a waste of resources.Therefore the present study aimed at investigating the extraction,structure characterization and physical properties of shaddock peel polysaccharide.The main results of this research are as follows:1.Microwave assisted enzymaticd was used to extract polysaccharide from shaddock peel.On the basis of single factor test,the cellulase/pectinase ratio?microwave time and microwave power were selected as independent variables to shaddock peel polysaccharide extraction rate response by using Box-Behnken experimental and response equation.The regression equation is:Y=-30.75500+0.12162A-13.05500B+34.43500C+0.023125AB-9.37500E-003AC+4.50000BC-1.15527E-004A2-1.33000B2-14.93000C2.The results showed the optimal extraction conditions were as follows:cellulase/pectinase of 1.3,reaction temperature of 50? enzymolysis time of 30min,pH of 3,solid-solvent ratio of 1:40,microwave power of 720W and microwave time of 2.5min.The extracted utilization rate of shaddock peel polysaccharides under these conditions was 22.8%.2.The polysaccharides extracting from the shaddock peel were purified by DEAE-52 fiber ion-exchange column,three components SPP-A?SPP-B and SPP-C were collected,respectively.The recovery rate of SPP-A,SPP-B and SPP-C were 12.20%?37.40%and 10.40%,respectively.The total recovery rate is 60%.The purity of polysaccharide was determined by UV and Sephadex G-100 chromatography column.3.The purified fractions of SPP-A,SPP-B and SPP-C were characterized by Fourier-infrared spectroscopy(FT-IR).Infrared spectroscopy analysis indicated that the three samples had typical peaks of polysaccharide.The SPP-A contained a furanose group,SPP-B and SPP-C both belonged to ?-type hetero polysaccharide.4.The purified fractions of SPP-B were characterized by Ultraviolet-Visual(UV-Vis),gas chromatography(GC),Congo red reaction and iodine reaction.Gas chromatography(GC)confirmed that the SPP-B were heteropolysaccharides,which were composed of glucose,mannose and arabinose with molar ratio of.Congo red reaction indicated that the SPP-B fractions contained helical structures.5.The solubility and viscosity of polysaccharide from shaddock peel were studied.The solubility of polysaccharide is affected by tempretrature,concentration and pH intensively.The viscosity of polysaccharide solution is affected by tempretrature and pH.The effect on the viscosity of polysaccharide of alkaline solution dissolve easilythan in acidic solution.