Research On Extraction,Purification,Structural Analysis And Antioxidant Activity Of Polysaccharides From The Ginger Skin

Ginger belongs to the perennial herbaceous plant.In addition being used as a spice,ginger is a very high value of medicinal plant,with significant antibacterial anti-inflammatory,antioxidant,anti-cardiovascular abilities and can control cerebrovascular diseases and possesses other health functions.In recent years,ginger has been made into a wide range of processed products.With the increasing demand for the active ingredients of ginger,the prospect of it's processing has been broadened.With its processing comes by-products,such as ginger skin.In this paper the author optimized extraction of ginger polysaccharides from ginger skin.The ginger polysaccharideswere isolated and purified and characterized and their antioxidant activity analyzed.The main results were as follows:1.Using orthogonal experiment,optimized ginger skin polysaccharide water extraction process,the author foundout that the optimum extraction conditions were:temperature of 85?,extraction time 2.5h,extract liquid than 1:35g/mL.Under these conditions,ginger polysaccharide extraction was rate of 1.92%.2.Three kinds of ginger polysaccharides:GE-1,GE-2 and GE-3 were isolated and purified by DEAE-52 ion chromatography and G-100 dextran gel chromatography.The total sugar content for the three polysaccharides were 98.06%,97.41%,97.89%,respectively as determined by the Phenol sulfuric acid method.High performance gel filtration chromatography was used to determine the molecular weight of the polysaccharide components.The formula weights was 462 kDa,194 kDa and 376 kDa.3.It was found that GE-1 of ginger polysaccharide was mainly composed of mannose,glucose,xylose in the molar ratio of 1.25:6:1 as well as trace amounts of galactose by the adoption of pre column derivatization high performance liquid chromatography(HPLC)method.GE-2 was mainly composed of mannose,glucose and galactose in the molar ratio of 2.51:9.25:1.GE-3 was mainly composed of mannose,ribose,galactose and Arabia sugar in the mole ratio of 17.39:1:1.89:1.23.The UV spectrum scanning showed that the three kinds of polysaccharide fractions were without apparent nucleic acid and protein absorption peaks,which was an indication of good purification efficiency.Infrared spectrum analysis results showed that GE-1,GE-2 and GE-3 contained the characteristic absorption peak of polysaccharide,and GE-1 had xylose absorption peak.4.The vitro antioxidant analysis showed that GE-1,GE-2 and GE-3 had strong scavenging effect on hydroxyl free radical and hydrogen peroxide and superoxide anion radicals.The radical scavenging effect was dose dependent.GE-1,GE-2 and GE-3 also had a certain ability to clear the DPPH free radical and the ability to restore it.