| Lycium bararum.L is a traditional Chinese herbal medicinal and edible,with nourishing yin and tonifying kidney,Liver eyesight and other effects.In recent years,artificial cultivation of Qaidam Basin in Qinghai has developed rapidly and the total planting area has exceeded Ningxia.The unique natural conditions and clean ecological environment of the Qaidam Basin have no pollution in the 100-km radius,large temperature difference between day and night,lighter diseases and insect pests,low frequency of pesticide application,and low detection rate of pesticide residues,making the fruit large and full,fleshy and nuclear small,bright color and sweetness.In the production process,a large amount of defects will occur in the production process.Usually,these defective products are discarded as waste products,causing great waste and increasing the company's production costs.After testing,the remaining fruits in the alfalfa are rich in the content of polysaccharides,the efficacy is clear,and they have a broad market prospect.This study took the defective fruit produced in the process by the Lycium bararum.L production enterprises in the Qaidam Basin,Qinghai Province as the research object.Based on the previous research work of the research group,microwave extraction technology was adopted and the response surface method was used to extract the polysaccharides from the medlar residue.The process was optimized and its polysaccharides were purified and their antioxidant activity was explored.The results are as follows:1.Microwave-assisted extraction of residual polysaccharides from defective fruit was conducted.On the basis of the single factor test,the microwave assisted extraction process of the residual fruit polysaccharide of Lycium barbarum was optimized by the response surface Box-Behnken design.The results showed that the ratio of material to liquid,extraction time had a significant effect on the yield of polysaccharides,and the interaction effect of material-liquid ratio and extraction time had a significant effect.The optimal process parameters were as follows: ratio of material to liquid 1:30,extraction time 2 min,microwave power 350 W.Under this condition,the yield of the polysaccharide with residual fraction was 8.464%,which was only 0.329% with the predicted value of 8.793%.It is verified that there is a good fit between the predicted value and the experimental value of the equation.2.The selection of the residual deprotein method of Lycium barbarum.During the extraction process of the extraction of the residual fruit polysaccharide of Lycium barbarum,protein accounted for a large proportion,affecting the quality of polysaccharides,using three methods to deprotein.Compared to the three methods of three chloroacetic acid method,Sevage method and hydrochloric acid method,it was found that the three chloroacetic acid method was more suitable for the removal of polysaccharide protein,the deprotein rate was 72.6%,and the loss of polysaccharide was lost.The rate is 15.3%.The deproteinized rates of Sevage and hydrochloric acid were 65.3% and 53.6% respectively,and the loss rates of polysaccharides were 51.3% and 56.5% respectively.Through the comparison of data,the three chloroacetic acid method is the best decolorization process.3.In vitro antioxidant activity of Polysaccharides from Lycium barbarum fruit.In this experiment,Vc was used as a positive control,DPPH oxidation method,salicylic acid method and reduction capacity were measured,and its antioxidative activity in vitro was investigated.The experimental results show that: the residual fruit polysaccharide polysaccharides on DPPH.The scavenging ability of the residual fruit polysaccharide of Lycium barbarum on DPPH was lower than that of Vc,but its scavenging ability was also increased as the mass concentration increased,especially when the mass concentration of the polysaccharide solution reached 1.4mg/mL,the removal rate of the residual Fruit Polysaccharides of Lycium barbarum was 62.07 %,which was close to the removal rate of Vc.The remaining fruit polysaccharides have a strong ability to scavenge hydroxyl radicals.When the concentration of polysaccharides in the remaining fruits reached 1.4 mg/mL,the highest clearance rate was 83.83%,and the removal capacity was stronger than that of Vc.The reducing ability of the remaining fruit polysaccharide is slightly lower than that of Vc,but the reducing ability is continuously enhanced within the range of polysaccharide concentration,and there is still a certain degree of antioxidant capacity within the determined mass concentration range.This experiment is based on the abundant Lycium bararum.L planting resources in the Qaidam Basin,Qinghai Province.It uses the residual fruit produced by the Lycium bararum.L production enterprises during the preparation of the thorium series products as raw materials.As well as its antioxidant activity,it provides an experimental basis for the extensive comprehensive development and utilization of scorpion sorghum. |
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