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

Ginger belongs to the perennial herbaceous plant.It's China's traditional medicine and commonly used spices.Ginger flavoring and ginger juice beverage are two kinds of popular ginger products,but in the process of production and processing,ginger residues become by-products,which greatly causes the waste of guinger resource.In this paper,the process of extracting ginger residues polysaccharides from ginger residues were studied,and the structure and antioxidant activity of the purified polysaccharide were analyzed.The main results are as follows:1.The optimum extraction conditions were ultrasonic power 400W,liquid/solid ratio 40mL/g,ultrasonic time 17min,ultrasonic temperature 74 ?.Under the optimum conditions,the optimum extraction conditions were as follows:The crude polysaccharides yield of ginger residue was 4.81%.2.GE-1,GE-2 and GE-3 were separated and purified by DEAE-cellulose ion-exchange chromatography and dextran G-100 gel chromatography to obtain the polysaccharides from ginger residues.GE-4,GE-5 and GE-6 were separated and purified from hot-water-extracted ginger residue polysaccharides.The physical and chemical properties of crude polysaccharides extracted from the two methods and their purified components were determined by physical and chemical methods.3.The results showed that the purity of the polysaccharides was high,the molecular weight of the purified polysaccharides GE-1,GE-2,GE-3,GE-4,GE-5 and GE-6 respectively.40.562 kDa,868.135 kDa,892.719 kDa,89.125 kDa,939.786 kDa,1007.926 kDa.The GE-1 and GE-4 were composed of mannose,rhamnose and glucose,and the molar ratio of GE-1 was 17.56:7.72:74.72.The molar ratio of GE-4 was 19.40:9.36:58.05.GE-2 is composed of mannose,rhamnose,glucose,xylose and arabinose in the same composition as the monosaccharide of GE-5.Among them,the molar ratio of mannose,rhamnose,xylose and arabinose in GE-2 was 18.13:9.03:8.97:5.04.The molar ratio of each monosaccharide in GE-5 was 11.84:9.36:12.68:8.07.GE-3 is composed of mannose,rhamnose,galactose,xylose and arabinose in the same composition as GE-6.The mannose,rhamnose,galactose,xylose,The mole ratio of arabinose was 8.32:9.01:4.33:12.19:6.87;the composition of monosaccharide in GE-6 was 11.33:13.90:10.96:4.73:9.07.The results of infrared spectroscopy showed that the six polysaccharide components contained the characteristic absorption peak of the polysaccharide,which was pyranose.The results of nuclear magnetic resonance experiments showed that the structural analysis of polysaccharides in ginger residues were consistent with the results of monosaccharide composition analysis and infrared spectroscopy.The three polysaccharide components extracted by ultrasonic were ?-type pyranose,Polysaccharide components GE-4 and GE-5 are ?-type pyranose,GE-6 is a-type pyranose,and mainly composed of L-rhamnose,D-glucose,D-mannose and D-galactose4.The antioxidant activity of ginger residues polysaccharides of ultrasound-assisted extraction were higher than that of hot-water-extracted.The order of scavenging activity of DPPH radicals was:GE-3>crude polysaccharides of ultrasound-assisted extraction>GE-6>GE-5>GE-2>crude polysaccharides of hot-water-extracted>GE-1>GE-4-the order of scavenging activity of superoxide radicals was:GE-3>GE-6>crude polysaccharides of ultrasound-assisted extraction>crude polysaccharides of hot-water-extracted>GE-1>GE-2>GE-4>GE-5.The order of scavenging activity of hydroxyl radical was:GE-2>GE-5>crude polysaccharides of ultrasound-assisted extraction>GE-4>GE-1>crude polysaccharides of hot-water-extracted>GE-3>GE-6.