| Zha-Chili are fermented chili products with the characteristics of cloud,Guizhou,Sichuan,Chongqing minority areas and areas where the Han nationality and ethnic minorities live together.In this experiment,different starch sources were used as ingredients to prepare the pepper,which was fermented under natural conditions.The changes of polysaccharide content in different fermentation time of different starch sources were studied,and the optimum fermentation time was selected according to the change of polysaccharide content and antioxidant effect in vitro.The optimization of the extraction process and the further study of separation and purification were carried out,and the antioxidation and structure of the purified polysaccharides in vitro were studied.The main contents of the study are as follows:1.Selection of optimal fermentation time for different starch sources of Zha-Chili(1)Changes of polysaccharides content in different starch sources and different fermentation periods of Zha-ChiliThe content of polysaccharide increased first and then decreased with the increase of fermentation time.The peak value of polysaccharide content in three kinds of sea pepper appeared at 40 days after fermentation,and the content of crude polysaccharide extracted by ultrasonic assisted extraction was higher than that of water extraction and alcohol precipitation.Considering the extraction rate of polysaccharides,the study of polysaccharides from sea pepper was carried out by ultrasonic assisted extraction.(2)Antioxidant function of crude polysaccharides from different starch sources in vitroThe peak value of crude polysaccharides of three kinds of pepper appeared in fermentation for 40 days,the peak value of scavenging·OH activity was 40 days after fermentation,and the ability of scavenging DPPH free radical was higher at 20 ~ 40 days of fermentation.According to the above results,the better fermentation time is 20 ~ 40 days,combined with the extraction rate of polysaccharides from different fermentation time,the next step is to select the 40 days fermentation time.2.Optimization of extraction conditions and purification of crude polysaccharides from different starch sources of Zha-Chili(1)Optimization of extraction conditions for crude polysaccharidesThe optimization results of the extraction process of the crude polysaccharide were as follows: the ratio of the material to liquid was 1:36.32,the extraction times was 2.78,the extraction time was 22.81 min,the extraction temperature was 48.38?,the extraction rate of the crude polysaccharide was 14.99%,and the optimization result of the extraction process of the crude polysaccharide from the indica rice pepper was that the ratio of the material to liquid was 1:40,the extraction times was 2.83,and the extraction time was 25 min,the extraction rate of crude polysaccharide was about 10.24% when the extraction temperature was 49.02?,and the optimum extraction process of the crude polysaccharide extraction process was as follows: the ratio of material to liquid was 1:38.59,the extraction times was 2.73,the extraction time was 22.72 min,and the extraction temperature was about 9.23% when the extraction temperature was 52.65?.(2)Purification of crude polysaccharidesThe crude polysaccharide extracted from glutinous rice and sea pepper was dialyzed by income,after removing protein,After fractionation with DEAE-52 cellulose column chromatography,three elution components were N1,N2,N3.The N1,N2 was further purified and eluted by dextran gel Sephadex G-50.N1 A,N1B,N2 A,N2B were obtained.The final selection of N1 A,N2A component considering yield.Purification of crude Polysaccharide from Indica Rice Pepper,X1 A,X2A.Purification of crude Polysaccharide from Maize Pepper Y1 A,Y2A.Finally,the six components of N1 A,N2A,X1 A,X2A,Y1 A,Y2A was carried out the next step of the study.3.Study on the Antioxidant activity and structural characteristics of Polysaccharide from Zha-Chili(1)Study on Antioxidant activity of Polysaccharide from Zha-ChiliGlutinous rice polysaccharide had the highest reductive activity,followed by maize,and indica rice sea pepper had the lowest reducing capacity.Compared with the crude polysaccharides,the antioxidant activities of the polysaccharides isolated and purified were greatly improved.The DPPH free radical scavenging activity of indica rice sea pepper polysaccharides was the lowest,and the activity of glutinous rice and corn sea pepper polysaccharide was the same.(2)Analysis of basic Physicochemical Properties and composition of PolysaccharideThe basic physical and chemical properties of the six polysaccharides obtained from the three kinds of sea pepper were as follows: the solubility of the six components in water was not high,and they were insoluble in high purity acetone,ethanol,benzene,ether and other organic solvents.The six polysaccharides do not contain polyphenols,starch and reducing sugar,but contain partially incomplete protein.The analysis of the composition of polysaccharides showed that the uronic acid content were 6.28%,7.57%,4.86%,4.29%,5.74%,5.13%.The correlation between the antioxidant activity of each polysaccharide component and the content of uronic acid was analyzed.The results showed that the correlation coefficient between the reducing ability of polysaccharide component and the content of uronic acid was 0.994,which was significant(P < 0.01).There was a significant positive correlation between the reducing ability of polysaccharides and the content of uronic acid.The quantity has no correlation.(3)Purity Identification of PolysaccharideThe elution curve of the six polysaccharides was a single symmetric peak after being classified by Sephadex G-100 dextran gel column,indicating that the six polysaccharides were pure polysaccharides.(4)Molecular weight of polysaccharidesThe molecular weight of each component is:22387Da,18621 Da,26303 Da,22186 Da,31623 Da,13203Da.(5)Congo red analysisThree kinds of Polysaccharide of Sea Pepper complex with Congo Red complex showed a significant red shift in different concentrations of sodium hydroxide compared with the.That is,the maximum absorption wavelength of polysaccharides and Congo red solution is higher than that of blank Congo red solution,and the variation trend of maximum absorption wavelength of polysaccharides with Congo red solution under alkaline condition can be seen. |
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