Study On Phytosterols Extraction Process From Rapeseed Oil Deodorizer Distillate

With very important physiological functions, phytosterols is hailed as "the key to life". The applications of phytosterols involve medicine, cosmetics, food, optical products, feed, paints, pigments, resins, paper, textiles, pesticides and herbicides and so on. In recent years, the demand for phytosterols is rising sharply, with fermentation production of steroid hormones on more and more products. As the physiological function of phytosterols continually deepening understanding, its medicinal value is paid increasingly more and more attention and phytosterols have become concerned about hot spots which have attracted worldwide attention.Oil production and oil consuming is huge in China. By-product of the industrial grease contains a wealth of plant sterols resources, and so abundant phytosterols in the rapeseed oil deodorizer distillate. Until now, there are many methods which extracted phytosterols. The common methods are solvent crystallization, complexing, saponification, distillation, absorption, supercritical CO₂ extraction, enzymatic, etc. They are mostly low-yield and high cost in these methods. Some of them can not be achieved in industrial production. Therefore, to explore the economic and efficient production technologies seems imminent in theory and application value and economic value.For these reasons, phytosterols extraction process from the rapeseed oil deodorizer distillate was studied in this paper. The main findings were as follows.1. The results of single factor experiments and orthogonal experiment of methyl esterification showed that: （1）With the increasing of methanol usage, concentrated sulfuric acid usage, methyl esterification time and temperature, rate of methyl esterification was rising, but methanol usage, methyl esterification time and temperature had no obvious effects on the phytosterols yield, and the phytosterols yield reduced with concentrated sulfuric acid usage; （2） The suitable process parameters of methyl esterification were the ratio of methanol and raw materials （W : W） 0.5 : 1, the ratio of concentrated sulfuric acid and raw materials （W: W） 0.05:1, methyl esterification time 3.5±0.5 h, and methyl esterification temperature from 60 to 65℃. Methyl esterification rate was 98%, the phytosterols yield more than 74%.2. The results of single factor experiment and orthogonal experiment of saponification showed that: （1） With the increasing of methanol usage, sodium hydroxide usage, time and temperature, saponification rate was rising. The phytosterols yield increase with methanol usage and the phytosterols yield was lowed by sodium hydroxide usage rised. The effects of saponification time and temperature on the phytosterols yield were firstly rising and then declining; （2） The amount of concentrated sulfuric acid and acidification time had no significant effect on the phytosterols yield when acid reaction; （3） Saponification process parameters were the ratio of methanol and raw materials （W: W） 0.5:1, the ratio of sodium hydroxide and raw materials （W: W） 0.025:1, saponification time 4.0±0.5h, saponification temperature from 60 to 65℃. The appropriate parameters of acidificate reaction were the ratio of raw materials and concentrated sulfuric acid （W: W） 0.075:1, acid solution time 1.5±0.2 h. Saponification rate was 98%, the phytosterols yield above 78%.3. The crude and refined phytosterols crystallization were studied. The results were : （1） The suitable parameters of crude phytosterols crystallization were the crystallization temperature 0±1℃, crystallization time 6±0.5 h, the stirring time was the crystallization time. （2）The suitable refining process of crude phytosterols was benzene: crude phytosterols （W: V） ratio was 1:2 - 3, reflux heating 2±0.5 h, then cooling crystallization , crystallization time 6±0.5 h, the stirring time was the crystallization time.4. Phytosterols extraction process from rapeseed oil deodorizer distillate, furthermore fatty acid methyl ester and V_E extracted was: firstly methyl esterification, then saponification, then cooling crystallization, then washing crude phytosterols by benzine and finally drying.5. This study determined that if 250 tons/year crude phytosterols （65%） were producted, there was the profit of 3.8073 million yuan and the margin rate 19.25%. it was estimated that the cost of fixed assets （200 million） would be recovered in seven months. It would produce substantial economic benefits.