Extraction, Isolation, Purification, Antibacterial And Antioxidative Activity Of Polysaccharides From Fortunella Margarita

Fortunella margarita(Fortunella margarita (Lour.) Swingle) belongs to Rutaceae, Aurantioideae, Citreae, Citrinae, which is one of the most well-known specialty fruit in China. It has rich nutrition and special healthy value. Extraction technology, purified technology, anti-bacterial activity and anti-oxi dative effect of Fortunella margarita polysaccharides have been studied in this paper. Therefore,this study was filled blank in research field, provided the basic data and scientific basis for the application of natural Fortunella margarita polysaccharides.(1) With Youxi Fortunella margarita as experiment material, the best water extraction technology of Fortunella margarita polysaccharides was studied. The effect of water/material ratio, temperature, time, ethanol concentration and extraction times were studied on the extraction rate of Fortunella margarita polysaccharides and the conditions of extraction were optimized. The optimal conditions of polysaccharides extraction were obtained as following:the water/material ratio38:1(mL/g), extraction temperature88℃, extraction time2.5h, ethanol concentration70%, and that extraction rate could reach to1.81%with three-times extraction.(2) With Youxi Fortunella margarita as experiment material, the best ultrasonic-assisted and microwave-assisted extraction technologies of Fortunella margarita polysaccharides were studied. The optimal conditions of ultrasonic-assisted extraction were gained as following:the water/material ratio26:1(mL/g), time72min, extraction temperature45℃, ultrasonic power180W, and that extraction rate could reach to4.03%with one-time extraction. The optimal conditions of microwave-assisted extraction were gained as following:microwave power640W, the water/material ratio27:1(mL/g), time21min, particle size60, and that extraction rate could reach to5.18%with one-time extraction. Compared with traditional water extraction method, the extraction rate of Fortunella margarita polysaccharides were obviously enhanced by the ultrasonic-assisted and microwave-assisted extraction methods.(3) After concentrating and freeze drying, the dry powder of Fortunella margarita crude polysaccharides (FMP1) was obtained. With FMP1as experiment material, the best technology of isolation and purification of Fortunella margarita polysaccharides were studied. The technology of removed protein of Fortunella margarita polysaccharides was studied by combination of Papain and Sevag. The best technological conditions of removed protein were obtained as following:the content of enzyme120U/mL, enzymatic hydrolysis time80min and enzyme temperature40℃. Under the conditions above, the rate of removed protein could reach to75.88%, the rate of losing polysaccharides was5.45%. Then treated polysaccharides with Sevag three times, the rate of removed protein could reach to85.18%, however, the rate of losing polysaccharides was14.16%.The decoloring technology of Fortunella margarita polysaccharides was studied with D101macroreticular resin. The best technological conditions of decolorization were obtained as following:pH5-6, decoloring temperature of40℃, flow rate of2BV/h. Under the conditions above, the rate of decolorization could reach to88.24%, the rate of losing polysaccharides was15.65%. FMP2was obtained from FMP1after removed protein, decolorization, reversed water dialysis24h, concentration and freeze drying.(4) With FMP1and FMP2as experiment material, Anti-microbial activity of Fortunella margarita polysaccharides was studied in vitro. The results showed that Fortunella margarita polysaccharides have some antimicrobial effect on Staphyloccocus aureus Rosenbach, Salmonella, Escherichia coli, Bacillus subtilis, Pseudomonas. Anti-microbial activity of FMP1is superior to FMP2. The anti-microbial effect of Fortunella margarita polysaccharides on bacteria is better than its on fungi. As for the same strains, the more the dose of polysaccharides is, the better the anti-microbial effect is. The minimal inhibitory concentration(MIC) of FMP1on Staphyloccocus aureus Rosenbach, Salmonella, Escherichia coli, Bacillus subtilis, Pseudomonasare3.1mg/mL,50.0mg/mL,12.5mg/mL,12.5mg/mL,12.5mg/mL respectively.(5) The capacity of Fortunella margarita polysaccharides FMP1and FMP2on scavenging hydroxyl radical (·OH), superoxide anion radical (O2-·) and1,1-diphenyl-2-picrylhydrazyl radical (DPPH-) were studied in vitro, which were compared with the effect of Vc. The result showed that FMP1and FMP2have a certain capacity on scavenging·OH,O2-·and DPPH-, and the efficiency of scavenging is increased by the concentrations. The capacity of scavenging free radical of FMP1is better than FMP2. When its concentration was2.0mg/mL, the capacities of FMP1on scavenging the three kinds of free radical were62.29U/mL,38.88U/mL,19.03%respectively. In addition, the effect of scavenging hydroxyl free radical of FMP1is better than its of Vc.