Rebaudioside A In Different Original Leaves Of Stevia Rebaudiana And Extracting Process Optimization Of Steviol Glycosides

Stevia glycoside is a no-digesting, non-toxic sweetener with low quantity of heat, high sweet taste, as300times as sucrose sweetness, fitting for all the Food industry fields, suiting for patients with diabetes, hypertension, arteriosclerosis, obesity, dental caries disease;recently, stevia glycoside research is a hot spot.In this research,determibation of rebaudibaA content of stevia leaves from10provice including15city was carried out, then suitable resin was chosed from10kinds of resin to purificate total glycoside and established the best purification process, stevia leaves water extraction process and recrystallization process were optimazed, Finally,main composition of stevia slag and stevia glycosides were identified.1. The RA determination of stevia leaf from10provinces including15places was carried out, the results showed that different regions stevia has different RA content, in the range of0.25%-17.50%. Shaoxing Zhejiang produced stevia has the highest RA content, at7.50%, followed by Hangzhou Zhejiang, at14.0%, Aral xinjiang in third place, at13.75%, Buyang anhui has the lowes RA content, at0.25%.This reaserch provides basic quality assessment of stevia.2. In this research,10kinds of resin including polar and nonpolar, weak polarity, absorption quanity of stevia glycosides were studied, the results showed that D101resin was the best selection,55.7mg/g, followed by S-8, AB-8, ADS-21, HP20, all of them were fit to be used in stevia giycoside purification, Resin adsorption ability strong or weak has no correlation with resin polarity. S-8and D101resin was suitable for stevia glycoside enrichment. In This research D101resin was choosed to seperate and purificate total glycoside. the best extracting process was:stevia extraction filtered by D101Coloumn resin, washed by3%NaOH to neutral, then washed by90%ethanol elution, got high purity of total sugar concentration liquid, RA content of Stevia glycosides enrichment was45.05%. 3. optimization of stevia leaf water extract process and recrystallization were carried out, resutts showed that the optimal water extraction condition:constant temperature60℃water, immerse15h. material liquid ratio (10:1), Under the condition extract rate is highest,38.25%; The optimal recrystallization Separation of stevia glycoside facilitation programs for:, ethanol method of recrystallization condition:100%ethanol as the solvent, and solid-liquid ratio10:1, placed15h time, under this condition,recrystallization rate is highest, at61%.4.Two Compounds from Stevia slag95%alcohol extraction was seperated by column chromatography, such as Silca-gel,Identified through nuclear magnetic resonance (NMR) spectroscopy, carbon and hydrogen spectrum analysis, results showed that β-sitosterol and quercetin respectively.5. One compound seperated from stevia glycoside by HPLC chromotography and Identified through nuclear magnetic resonance (NMR) spectrum analysis as Rebaudina A.