Study On Extraction,Degradation Condition Optimization Of Passifora Edulis Sims Peel Polysaccharide And Its Bioactivity

In this paper,Passiflora edulis Sims peel from the Guilin was used as raw material to study the technical conditions for the extraction of polysaccharides,and the degradation polysaccharides were studied by acid method,ultrasonic assisted acid method and enzymatic method.The differences in structure and biological activity of polysaccharides under different degrees of hydrolysis from Passiflora edulis Sims peel under different degrees of hydrolysis were explored.It will lay a foundation for more in-depth research and development of Passiflora edulis Sims peel polysaccharides in the future.The results of the study are as follows1.Using microwave-assisted extraction of polysaccharides from Passiflora edulis Sims peel.On the basis of single-factor experiments,the parameters optimized by response surface method were as follows:material-liquid ratio 1:27 g/mL,extraction time 3.4 min,microwave power 420W under optimal conditions,and the extraction rate of polysaccharide was 14.12%±0.42%,which is 1.5 times the extraction rate of traditional water bath polysaccharides.2.Using the·OH clearance rate as an indicator,the biological activity of corresponding degradation fragments of WPEP was examing under different degradation conditions by acid method,ultrasonic assisted acid method and enzymatic method.Acid Degradation with a concentration of hydrochloric acid of 0.1 mol/L and the working temperature of 60°C as well as the reaction time of one hour,produced A-WPEP,whose the clearaning rate of·OH reached the highest of 26.55%,the degree of hydrolysis was 6.41%;Ultrasound-assisted acid degradation was the best parameters at 100 W ultrasonic powers,10 min ultrasonic time,and 50°C temperature,the cleaning rate of U-WPEP was 33.28%,and the degree of hydrolysis is 7.23%;Enzymatic degradation at the optimal process parameters of pH 5,enzymolysis time 30 min,temperature60°C,the cleaning rate of M-WPEP was 34.53%.,and the degree of hydrolysis was 25.30%.3.The structures of four polysaccharides with different degrees of hydrolysis,WPEP,A-WPEP,U-WPEP and M-WPEP,were characterized by HPLC,FTIR,?-elimination reaction,Congo red,XRD and SEM.In HPLC experiments,the average molecular weights of WPEP,A-WPEP,U-WPEP,and M-WPEP were 1.18×10⁵ Da,1.14×10⁵ Da,1.06×10⁵ Da,and 9.24×10⁴Da.In the infrared spectrum,the characteristic absorption peaks of four polysaccharides in the characteristic regions are basically consistent;in the fingerprint region,compared with other three polysaccharides,M-WPEP has a significant difference in the absorption peaks of the aldehyde functional groups.In the?-elimination reaction,the glycopeptide bonds of the four polysaccharides all belong to the N-glycopeptide bond.In the Congo red experiment,the four polysaccharides contained a triple-helix structure and the three-helix spiral structures of A-WPEP and U-WPEP increased with acid and ultrasound-assisted acid degradation.In the XRD pattern,the 2?of the four polysaccharides appeared weaker and wider diffraction peaks near 21°,showing a low degree of crystallinity,and the interior of the four polysaccharides was an amorphous structure.Compared with the other three polysaccharides,the intensity of the diffraction peak of M-WPEP significantly increased,indicating that the enzymatic method has a greater degree of damage to its internal crystallinity.In the SEM image,there are large differences in the structures of WPEP,A-WPEP,U-WPEP,and M-WPEP.The surface of WPEP is large and smooth;the surface of A-WPEP and U-WPEP is rod-shaped and has a rod-like section;the surface of M-WPEP is in the form of small pieces.4.The DPPH radical and potassium ferricyanide methods were used to evaluate the antioxidant activity of four different degrees of hydrolysis of Passiflora edulis Sims peel polysaccharides.The results showed that WPEP,A-WPEP,U-WPEP and M-WPEP have a certain anti-oxidation activity,and the magnitude of the anti-oxidation ability is positively correlated with the sample concentration.When the sample concentration was 1.5 mg/mL,DPPH·clearance rates of WPEP,A-WPEP,U-WPEP,and M-WPEP were 92.76%,53.29%,72.88%,and 68.39%,respectively,the IC₅₀ values were 0.29 mg respectively./mL,1.34 mg/mL,0.42 mg/mL,and 0.98mg/mL;reduction capacities were 0.55,0.22,0.20,and 0.32,respectively.Under the same conditions,compared with the antioxidant activity of WPEP,the antioxidant activity of A-WPEP,U-WPEP and M-WPEP both decreased.