Study On Separation,purification,digestion And Absorption Of Polysaccharide From Scallop Waste Liquid

As an important seafood resource in the world,scallops have good economic and nutritional value.In this paper,polysaccharide from scallop waste liquid was isolated.The polysaccharides of scallop waste liquid were separated,purified and simulated digestion experiments were carried out to obtain component I,component II and component III,as well as saliva digestive polysaccharide,gastric fluid digestion polysaccharide,intestinal digestion polysaccharide.The method of protein removal,basic ingredients,structure analysis,antioxidant activity,and cellular immunoactive activity were studied.The main research results are as follows:(1)Using scallop waste liquid polysaccharide as raw materials,the purity and recovery rate of polysaccharides after protein removal by enzymatic hydrolysis,trichloroacetic acid and Sevage methods were compared,and it was found that the purification effect of alkaline protease was better than other types of enzymes.Compared with Sevage method,TCA method was more suitable for purifying scallop waste liquid polysaccharide.After structural analysis,it was found that the protein removal method had little effect on the structure of the polysaccharide.(2)The scallop waste liquid polysaccharide is subjected to alcohol precipitation to obtain separated and purified raw polysaccharide.It was separated and purified by DEAE-sepharose fast flow,and three different components were obtained.Component I had the highest purity,and component III contained a large amount of uronic acid and protein.After separation and purification,the triple-helical structure of component I was disappeared,and the thermal stability of the polysaccharide was decrease,which indicated that the polysaccharide was more easily decomposed.According to the molecular weight and scanning electron microscope,the structures of component I,component II and component III were complex.In cell viability experiment of Raw 264.7,component I,raw sugar,and component III all had proliferative effects on macrophages,while component II had a certain inhibitory effect on cell viability.It was found that the four polysaccharides could improve the immune activity and the component ? had the best immune activity.(3)The polysaccharide of scallop waste liquid was digested continuously by simulated saliva,gastric juice and intestinal juice.The reducing sugar content gradually increased,a small amount of free glucuronic acid,galacturonic acid,and glucose were detected,and the protein content also changed to a certain extent.According to the molecular weight result,it can be seen that the molecular weight of scallop waste liquid polysaccharide changed significantly in the simulated digestion system,polysaccharide fragments less than 10 k Da exist in large numbers,and the polysaccharide samples were seriously fragmented.After digestion,the glycosidic bond signal weakened,indicating that the simulated digestion broke the glycosidic bond of the polysaccharide to form many small molecular fragments,the thermal stability of the polysaccharide was reduced,and the triple helix structure of the intestinal juice digested polysaccharide was disappeared.(4)The four polysaccharides have certain antioxidant capacity,and the antioxidant activity increased with the increase of concentration.In the ABTS,DPPH,and iron reducing power experiment,the results showed that intestinal juice digestion polysaccharide > saliva digestion polysaccharide> raw polysaccharide > gastric juice digestion polysaccharide.When the sample concentration reached 4 mg/m L,the saliva-digested sample has the strongest hydroxyl radical scavenging ability,reaching 89.27%,the nitrite scavenging ability disappeared after the scallop waste liquid polysaccharide was digested.It is speculated that the spatial structure of polysaccharides in the digestion system is destroyed,resulting in the lack of nitrite scavenging ability of the digested samples.In cell viability experiment of Raw 264.7,with the increase of the concentration of the four polysaccharides,the cell viability was enhanced,indicating that the four polysaccharides had a certain proliferation effect on macrophages.When the polysaccharide concentration reached 200 ?g/m L,NO The content of saliva digested polysaccharide was significantly increased and the NO content of saliva digested polysaccharide was the highest.The four polysaccharides had a certain promoting effect on the neutral red phagocytic ability of macrophages,indicating that the scallop waste liquid polysaccharide could improve the immune activity after digestion,and the saliva digested polysaccharide had the highest immune activity.