Study On The Degradation And Mechanism Of Auricularia Auricula Polysaccharide By Plasma In The Presence Of H₂O₂

Auricularia auricula polysaccharide has unique characteristics,such as the large molecular weight,large molecular volume and poor water solubility,natural agaric polysaccharides,which is not conducive to the biological absorption into the body and can’t exert functional activity in the body.It greatly limits the application of agaric polysaccharides.Studies have shown that the preparation of oligosaccharides by degradation treatment of macromolecular polysaccharides can solve the above problems and the degraded polysaccharides have higher functional activity.Therefore,it is that great significance and broad market prospect for biodegrading agaric polysaccharides to prepare highly functional oligomeric polysaccharides.As a new advanced oxidation technology,pulsed discharge plasma technology has been widely used in the degradation of biological macromolecules due to its remarkable advantages.H₂O₂ is an efficient and strong oxidant,and it has been widely studied as a physical technology synergistic measure due to its remarkable enhancement of physical field treatment effect.In this topic,the pulsed discharge plasma and H₂O₂ were used as the treatment technology,through which the degradation process,kinetic research and degradation numerical simulation of black fungus polysaccharide were performed,and the degradation rule was analyzed,and the optimal degradation condition and the maximum degradation rate were obtained.Under optimal degradation conditions,biodegradation products of different molecular weights of Auricularia auricula polysaccharide were prepared,and their structure characterization,solution chain conformation and functional activity analysis were carried out,and the co-degradation mechanism of pulsed discharge plasma and H₂O₂ was discussed.Under this condition,the degradation rate of degradation products with treatment time of 60,120,180min was 72.76,87.83,89.95%.In this topic,under the optimal degradation conditions for the degradation products of Auricularia auricula polysaccharide.The advanced structure of untreated and degraded polysaccharides was observed by modern techniques such as TG-DTG,DSC,SEM,AFM,X-ray diffraction,GPC,FTIR and NMR.The results show that the principle of synergistic degradation of pulsed discharge plasma and H₂O₂ was theα-configuration glycosidic bond on the polysaccharide branch was destroyed by cutting the glycosidic bond,but it had no effect on the main chain structure of the polysaccharide,and the essentialβ-pyranose configuration of Auricularia auricula polysaccharide did not change.The results showed that the degradation treatment made the molecular weight of the polysaccharide smaller and the molecular weight range narrowed,but the main structure did not change.It was observed that the interplanar spacing of the product decreased,the crystallites decreased,the crystallinity decreased,the thermal stability decreased significantly,the degree of aggregation decreased,at the same time,the downward trend is positively correlated with the degradation time.The degradation also leaded to the decrease of the aggregation degree of the polysaccharide molecules,and the chain structure gradually disintegrated to form a random line.In this topic,the DPPH scavenging capacity,ABTS scavenging capacity,total reduction capacity,superoxide anion scavenging capacity,ferric reduction capacity and inhibition of anti-linoleic acid oxidation system were used as antioxidant indexes to study the antioxidant activity of the degradation products of polysaccharides from Auricularia auricula were prepared under the optimal degradation conditions.The antimicrobial activity of biodegradation products of Auricularia auricula polysaccharide was studied by escherichia coli,staphylococcus aureus and bacillus subtilis.The results showed that the antioxidant capacity and bacteriostatic capacity of biodegradation products of Auricularia auricula polysaccharide prepared by pulsed discharge plasma and H₂O₂ were significantly improved,and positive effect and degradation time were positively correlated.In this topic,the effect of inactive groups on the degradation rate of polysaccharides by using tertiary butyl alcohol,manganese dioxide,carbon tetrachloride,benzoquinone and phosphate as shielding reagent in the process of degradation of polysaccharides by pulsed discharge plasma was studied.The change of·OH yield and H₂O₂ concentration in the system under different electrode spacing and initial concentration of H₂O₂ was studied.The results showed that:·OH and H₂O₂ were the main degradation substances in the system,and the influence of different active groups on the degradation effect was successively:·OH≈H₂O₂>·H>·O>hydrated electron,Meanwhile,H₂O₂ was mainly decomposed·OH through Fenton reaction.