Optimization Of Extracting Conditions And Study On Antibacterial Activity Of Polysaccharide From Ginkgo Biloba

In recent years,Ginkgo biloba extract developed from ginkgo and its preparation is one of the more popular natural plant productions.The leaves of Ginkgo biloba consist of polysaccharides,flavonoids,terpene lactones and other chemical ingredients,with anti-inflammatory,anti-bacterial,antioxidant and other biological functions.Polysaccharide is one of the most important functional compoments for Ginkgo biloba,which plays a strong role in scavenging reactive oxygen species and anti-lipid oxidation and antibacterial effect.In this paper,the preparation schemes of polysaccharides from Ginkgo biloba leaves were optimized,and the crude extracts of Ginkgo biloba polysaccharides were purified.The antibacterial properties of Polysaccharides were studied as well.Polysaccharide cling film was also investigated in order to lay the foundation for further development and utilization.The findings of this research revealed that:1.GBLP was prepared from Ginkgo biloba as raw material.The effects of the addition of cellulase and the effect of ultrasonic wave on the yield of GBLP and the content of polysaccharide were studied.The optimal method was selected as the combination of ultrasound and enzyme.Ultrasound-enzyme assisted water soluble alcohol precipitation Ginkgo biloba leaves were prepared and optimized by the single factor test and response surface test,which were assisted by ultrasonic and enzyme.The optimum extract conditions were as follows:In the power of 720w ultrasonic processing under 30 min,and add 0.8%cellulose enzyme in it,under 55℃ water bath after enzymolysis effect leaching 40 min.and the in leaching temperature is 80℃,the leaching time of 4.7 h,and solid-liquid ratio of 1g:50mL,the highest yield of polysaccharide was 12.8%,with 82.4%content of polysaccharide.2.The results showed that GBLP had the characteristic absorption peaks of polysaccharides and the absorption peaks of carboxylate salts,and the acidic polysaccharides of pyran rings were analyzed by IR spectroscopy.The composition of the polysaccharide determined by HPLC was:Man:Rah:Glc:Gal:Xyl:Ara:Fuc=1.28:3.35:1.42:3.58:1:2.66:2.75.Electron microscopic analysis of the microstructure of GBLP was fluffy irregular honeycomb,with certain pores.3.Different levels of antibacterial effect were revealed against Escherichia coli,Bacillus subtilis,Staphylococcus aureus and sarcina.Escherichia coli showed an extraordinary concentration at lmg/mL,compared with Bacillus subtilis 4mg/mL,sarcina 2mg/mL,Staphylococcus aureus 4mg/mL.On the expansion of Penicillium and Alternaria alternata also have antibacterial activity.4.According to the bacteriostasis of polysaccharides from Ginkgo biloba leaves,a daub type of antibacterial fresh-keeping film based on four single factor tests and orthogonal experiment’ results was developed.The best ratio of compound film was 1.5%acetic acid solution,2mL glycerin,2g GBLP and 1.5g beeswax,which exhibited a certain inhibitory effects on fresh fruits and vegetables.And the film is easy to clean,which is no poison,convenient and safe smear-type food cling film.This research provides a way for the resource utilization of ginkgo waste materials to reduce the environmental pollution caused by burning leaves,which will be significant research.