The Study On Extracting Phytosterol

Phytosterol is being studied widely and deeply by people in recently years,the result indicates phytosterol is an innoxious natural substance with high physiological activity and is called"the key of life".It can decrease the content of cholesterol in blood,make skin healthy and look well,improve the animal's growth and health. Phytosterol has been used in clinical medicine,steroid drug material,cosmetic and the animal's growth etc.The soybean oil deodorizer distillate (SODD) is by-product in the process of oil refining,containing plenty of phytosterol. HPLC is used as the qualitative and quantitative analysis method in this research. Methanol:water(v:v) 97:3 ; flowrate:1 ml/min;UV detection wavelength:210 nm;time:35 min;sampling amount : 20μl, external reference method is used for quantify.This research measures the content of phytosterol in the raw material is 9.55%(campesterol 2.63%,stigmasterol 2.52%,β-sitosterol 4.40%),proving that it is the excellent raw material for extracting phytosterol.The main compositions in SODD are free fatty acid,glyceride,VE and phytosterol.Because free fatty acid has high boiling point,the methylesterification can transfer free fatty acid into ester as much as possible.In this way the separation of free fatty acid is possible. The optimum technical conditions of esterification reactions are obtained by esterification orthogonal experiment as followed : SODD:methanol(Wt:V) 1:1.5, esterification temperature 60℃, catalyst: SODD (Wt: Wt) 20%.The esterification rate is 98.29% and the VE reservation rate is 95.75%.After methylesterification ,keep stationary to stratify and crystallize the above layer solution ,then rough sterols are obtained. The purity of rough sterol is 47.87% and recovery rate is 96.91%.Phytosterols are refined by recrystallization,furthermore,the optimum technical conditions of are obtained by orthogonal experiment as followed : rough sterols:n-pentanol(wt:v) 1:20, recrystallization temperature -5℃, recrystallization time 16h.The purity of refining sterols is 96.88%,the yield rate is about 91.68%. Phytosterols are composed of campesterol,stigmasterol andβ-sitosterol,β-sitosterol is obtained by recrystallization because the solubilities of campesterol,stigmasterol andβ-sitosterol change differently with temperature changes in n-pentanol.,the purity ofβ-sitosterol can reach 86%;the purity of stigmasterol can reach 93% after recrystallization,because campesterol and stigmasterol have different solubilities in cyclohexanone and n-pentanol.The above data provide a basis for industrialization production of extracting phytosterols and single sterol refining from the soybean oil deodorizer distillate.