| Luffa is a kind of common and edible plant,its chemical composition is complex and contains all kinds of active components.In recent years,the research of this plant polysaccharides has been paid much more attention and the reason is that this plant polysaccharide is a kind of natural material which has good biological activities,and it can be used for the treatment of various diseases and improvement of human health.However,the study of Luffa polysaccharide is still at the primary stage,studying Luffa polysaccharide will provide a theoretical basis for the development of the nature and also expand the Luffa polysaccharide product in the future.In this paper,extraction conditions,purification,physicochemical properties,antioxidant activity and structure of Luffa polysaccharide were studied,which provide the reference for the research and development of functional food Luffa.The contents and results are as follows:(1)The polysaccharide was extracted by ultrasonic enzyme method,and the process conditions were optimized by response surface methodology,the extraction rate of polysaccharide as index,the four factors which affect the extraction rate of polysaccharide were optimize,including the material liquid ratio,cellulase addition,ultrasonic temperature and ultrasonic time.In the process of extraction,the order of the factors which affects the extraction rate of the size were:the liquid material>cellulase addition>ultrasonic temperature>ultrasonic time;the optimization of extraction conditions were as follows:cellulase addition 5.6%,solid-liquid ratio 33:1,ultrasonic temperature 72,ultrasonic time 30min,under these conditions,the gourd polysaccharide extraction of the the rate was 16.74%,which indicates that this method can be used to optimize the extraction conditions of polysaccharide of Luffa better.The crude polysaccharide was named LCP.(2)LCP was used as the raw material,Sevage was used to remove protein,orthogonal experiment was used to optimize the conditions of protein removal.The results showed that in VCHC13:V butanol ratio was 3:1,the ratio of VLCP:Vse,vage was 5:1,the oscillation time was 20 min,the effect of removing protein was the best,the removal rate of protein was 26.73%,and the loss rate of polysaccharide was about 10.26%.(3)The decolorization test of the crude polysaccharide LCP was carried out by using macroporous resin.The adsorption of selected D301 macroporous resin by dynamic adsorption test,the final results showed that the concentration of sample was 3mg/mL,sample volume was 10mL,under the condition of 2.5mL/min,the sample flow rate of decolorization effect was the best,the decolorization rate was 74.05%and the retention rate was 68.92%.(4)The removal of protein after decolorization of Luffa LCP polysaccharide as raw material,using DEAE-52 cellulose chromatography,distilled water,0.1mol/L NaCl,0.2 mol/L NaCl and 0.5 mol/L NaCl was elutioned respectively,which can be concluded LCP I,LCP II,LCPIII,LCPIV four components,collecting the highest content of polysaccharide group LCPII,which the content of polysaccharide was 63.53%.The LCP ? was purified by Sephadex G-75 column chromatography,distilled water was used as eluent,which can be concluded that a single elution peak was obtained,and the concentration of LCP was collected after concentration,dialysis and lyophilization.According to the analysis of UV spectrum,it can be seen that LCP ?-1 contains almost no protein,polypeptide,nucleic acid and so on.(5)The results showed that LCP ?-1 had the characteristic absorption peak of polysaccharide and the ring structure of LCP ?-1 was contained in the monomer.The relative molecular mass of LCP ?-1 was 16766.(6)LCP?-1 is white flocculent solid,soluble in water,insoluble in ethanol,ether,acetone,ethyl acetate and other organic solvents.The results of chemical reaction showed that the sample contained polysaccharide components,and it contained no protein and starch.The determination results of antioxidant activity in vitro showed that Luffa polysaccharide LCP?-1 on hydroxyl radical scavenging capacity strong,loofah polysaccharide concentration was 1.0mg/mL,the clearance rate of up to 97.65%,which was similar to Vc;compared with Vc capacity,Luffa polysaccharide LCP?-1 on DPPH radical scavenging ability is weak,the polysaccharide concentration was 10mg/mL,the highest rate of scavenging was 39.62%;the total reduction ability of Luffa polysaccharide LCP ?-1 was far less than the reduction ability of Vc. |
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