| In this research,we isolated and purified three polysaccharides from pitaya peel and investigated their structure information and biological activity.In order to explore their physical-chemistry property of as a carrier of flaxseed oil to protect its biological activity,we applied the acid polysaccharide(PPP-3)to combine with sterol and glutenin and designed a new oil powder.The oil powder can delay the deterioration and have targeted slow-release action,the physical-chemical properties and in vitro digestion process demonstrated good application effect and promising development.1.Three polysaccharides(PPP-1,PPP-3 and PPP-4)were obtained after a series of processes of water extraction,decolorization and column purification etc.using pitaya peel.The structures of these three polysaccharides were studied by using UV spectrophotometer(UV),gel permeation chromatography(GPC),FT-IR,methylation analysis(GC-MS)and nuclear magnetic analysis.The results showed that the molecular weights of the three polysaccharides were 9.2 kDa,557.1 kDa and 947.3 kDa,respectively.The monosaccharide composition of PPP-1 were:Man,Rha,GlcA,GalA,Glc,Gal,Xyl with the molar ratio of 15.5:2.2:2.4:2.7:42.7:25.5:8.7;PPP-3:Man,Rha,GlcA,GalA,Gal,Xyl with the molar ratio of 20.4:21.9:3.3:48.8:3.1;PPP-4:Man,Rha,GlcA,GalA,Gal,Xyl with the molar ratio of 13.1:13.8:2.4:66.3:1.6:2.5.The possible structures of PPP-1,PPP-3 and PPP-4 were obtained by combining the results of infrared,methylation and nuclear magnetic analysis.The possible main backbone of these three polysaccharides(PPP-1,PPP-3 and PPP-4)were?4)-Galp-(1?4)-Glcp-(1?4)-Manp-(1?4)-Glcp-(1?;?4)-D-Gal p A-(1?2)-L-Rhap-(1?3,6)-L-Manp-(1 ?;?,2,4)-Rhap-(1?4)-GalpA-(1?3,6)-Manp-(1?4)-GalpA-(1?,respectively.2.The total reducing power,hydroxyl radical and DPPH clearance were used to evaluate the antioxidation of polysaccharides.The results showed that all three polysaccharides had antioxidant biological activity.The total reducibility and DPPH clearance of PPP-1 were significantly higher than other polysaccharides.We subsequently evaluated the anticoagulant activities and its fractions in vitro,using indexes to evaluate the properties,including activated partial thromboplastin time(APTT),thrombin time(TT)and prothrombin time(PT).The results showed that the PPP-1 hardly have anticoagulant activity but PPP-3 and PPP-4 were demonstrated good anticoagulant activity,which can prolong PT clotting time by 72.88%and 72.88%,respectively.The ACE enzyme inhibition activities of these three polysaccharides were determined by HPLC.The results showed that only PPP-3 had the ACE enzyme inhibition activity.The highest inhibition rate of PPP-3 was 48.2%when the polysaccharide concentration was 1mg/mL.PPP-1 and PPP-4 showed the promoting effect of ACE enzyme in the low concentration.3.According to the crystallization behavior of sterol and glutenin in flaxseed oil,sterol and glutenin were selected as the proportion of 4:6 to change the internal structure of flaxseed oil.Whey protein and pitaya peel polysaccharide(PPP-3)were used as the shell,tween 80 was used as the emulsifier and glutamine transaminase was used as the curing agent to prepare three kinds of oil powder(PE-0,PE-1 and SE-1).Liquid water content,embedding rate,stratification coefficient,average particle size,Zeta potential measurement,heat preservation acid value and peroxide value(POV)were studied.The results showed that the SE-1 was better than others in the physical and chemical properties.SE-1 can also effectively delay the oxidation of flaxseed oil during storage.Simulated digestion experiments were conducted in vitro.The results showed that SE-1 can effectively resist the simulated gastric acid digestion and showed the resistance in the simulated intestinal digestion process. |
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