| Our country is a big country which has many natural sweeteners. With the rapid development of economic and the improvement of people’s living standard, natural sweeteners have caused more and more attention and been widely applied in medicine, chemical and food industry, etc. Glycyrrhizic acid, glycyrrhiza flavonoids and stevioside were the common natural sweeters. And they were also used in the field of medicine due to the properties of anti-inflammation, antiviral and raise immunity. At present, the extraction and refinning were very important to promote the developemt of the sweeteners. Compared with traditional ways, the green and environmentally friendly and no pollution for the technology to be developed is necessary. The separation was applied in the industry, we need to study how to realize the high-efficiency separation of sweeteners in natural product by macroporous resin.The separation and purification of glycyrrhizic acid, glycyrrhiza flavonoids were systematically researched.(1) The separation and purification of glycyrrhizic acid was researched.Composite enzymatic technology was applied to extract glycyrrhizic acid from glycyrrhiza of the paper and to be separated by MAR. The adsorption capacity, adsorption ratio, desorption capacity and desorption ratio were measured to explore the separation efficiency of the MAR. and the examine devices was HPLC and UV spectrophotometer. After researching the static adsorption and desorption of the MAR to the glycyrrhizic acid and the glycyrrhiza flavonoids, and the dynamic adsorption and desorption of the MAR to the stevioside. the separation and purification effect of macroporous adsorption resin mixed bed to different adsorbate was investigated, and obtained the following results:①Composite enzymatic technology was applied to extract glycyrrhizic acid from glycyrrhiza and the suitable process conditions are studied, and obtained the following results: enzymolysis temperature was40℃, Composite enzymatic volumes was25mL, the ratio of solid to liquid was1:20, the extraction time was1.5h, the pH value of extracting solution was8, Extraction times were three, the extraction temperature was45℃, extraction temperature, ethanol volume fraction were70.00%, Ammonia water volume fraction were0.6%, under the optimal extraction conditions.the extraction rate87.56%, extraction volume was13.15mg/g. the extraction rate higher than traditional analytical methods.②The glycyrrhizic acid was used as adsorbate, On the basis of the similar principles of the performance parameter of the MAR and structural parameter of glycyrrhizic acid. Fourteen macroporous adsorption resin were choosed by static adsorption and desorption equilibrium, the mixed bed of LZ-49LZ-51LZ-54and LZ-66were the best separation effect of mixed bed for glycyrrhizic acid. The proportion of mixed bed was z-66=1∶1∶1∶1,under the optimal separation conditions, the adsorption rate can reach to80.00%, The desorption rate can reach to88.00%, the adsorption quantity was80.15mg/g, the desorption quantity was70.53mg/g and the purity can reach85.00%.③The glycyrrhiza flavonoids was used as adsorbate, Nineteen macroporous adsorption resin were choosed by static adsorption and desorption equilibrium and the adsorption and desorption quantity were measured by UV. The mixed bed of LZ-50and LZ-59were the best separation effect of mixed bed for glycyrrhiza flavonoids. The technological conditions of adsorption temperature, desorption temperature, adsorption and desorption pH and adsorption mechanism were further studied. Under the optimal separation conditions, the adsorption rate can reach to75.00%, the desorption rate can reach to89.23%, the adsorption quantity was15.24mg/g and the desorption quantity was13.60%mg/g and the purity can reach80.00%.(2) The separation and purification of stevioside was researched.Combined with separation theoretical research and practical application in our laboratory. Four macroporous adsorption resin were choosed by dynamic adsorption and desoiption equilibrium to crude extracts of the stevia and the adsorption and desorption quantity were measured by HPLC. The adsorption capacity, adsorption ratio, eluting capacity and eluting ratio were measured to explore the separation efficiency of the MAR. The mixed bed of LZ-72, LZ-73and LZ-75were the best separation effect of mixed bed for stevioside. The proportion of mixed bed was mLZ-72∶mLZ-73∶mLZ-75=3∶1∶3. The adsorption process accorded with polymolecular layer physical adsorption, under the optimal separation conditions, the purity of stevioside could reach92%after purification. |
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