Application Nanofiltration Purification Yacon Fos

Smallanthus sonchifolius[Poepp.& Endl.]H.Robinson,or named Yacon,is a member of the Asteraceae.It originally grew in Andes in South America as a kind of triditional tuber crop food of the native Indians tribes living there.The main component of yacon dry matter(DM) is oligofructans(fructo-,oligo-saccharides, FOS),which is commonly used as healthy food for patients suffering from diabetes or various digestive or renal disorders.In recent years,yacon has been successfully introduced in Yunnan and Hainan Provinces.This reserch focuses on the quantitative analysis of yacon saccharide components with phenol-H₂SO₄ method detected by UV detector and High performance liquid chromatography- differential refractive index detector(HPLC-RID),and examined the extraction and purification of the saccharide components in yacon with the same methods,and finally gets yacon FOS products with Nanofiltraiton technology.In the first part,two analysis methods that phenol-H₂SO₄ method and High performance liquid chromatography- differential refractive index detector(HPLC-RID) are established to measure the content of saccharide.Phenol-H₂SO₄ method is a simple and effective method for measuring the content of saccharide. Oligosaccharides first hydrolyzes to mono-saccharides with H₂SO₄,then quickly dehydrate and produce an orange-yellow color under the interaction with phenol,this solution has an especial absorption at 490nm.A fine linear correlation was get from 0.01051 mg/mL to 0.1051 mg/mL in the experiment.U ltimate^TMXB-NH₂(5μm, 4.6mm×250mm)column and Waters R401 differential refractive index detector were used in HPLC method.Chromatography was performed at 35℃,we used acetonitrile-water(92.5:7.5,v/v)for the mono-saccharides(fructose,glucose ) separation and acetonitrile - water(80:20,v/v ) for the oligosaccharides (sucrose,1-kestose,nystose,1^F- Fructofuranosylnystose) separation,six regression equations were acquired for quantitative determination,the six kind of saccharide components had a well liner correlation in the range of the experiment separately. The experiment measures the content of six kinds of saccharide in yacon,which grows up at Tengchong,Ynunan province.The experiment also measures the contents of yacon which deposited in the envireroment at 2℃and relative humidity 50%,and got the changing trend of saccharide components.Finally,we figured out the DM ratio in the fresh yacon tubers in this part.In the second part,we examined the preparation technology of yacon total saccharides extract.Using oligofructans content as index,we compared two extraction methods of Yacon that squeezed Juice directly and 80%ethyl alcohol extraction method.We chose the method of squeezed Juice directly and produced the Dry Powders of Yacon total saccharides extract by cryodesiccation.In the third part,we wipe off mono-saccharides and sucrose from yacon total saccharides extract by nanofiltraiton membrane separation technology in order to pure the FOS of yacon.This experiment adopt the indexes by elimination rate of mono-saccharides and sucrose and oligofructans recovery.First,the proper membrance was chosen based on hold-back molecular weight.Through the Orthogonal Design examined the permeation flux influenced on the condition of pH value,pressure and initial concentration.Through experiments,we optimized the operation conditions and got the optimal production technology condition.By cryodesiccation,the high-purity FOS products ofyacon can be made.