Recovery of vitamin E from deodorzing destillate of soybean oil purification

Deodorizing distillate - major by-product from purifying soybean oil, which contains three high value compounds like fatty acids, tocopherols (vitamin E), and phytosterols, is useful material for obtaining vitamin E. Firstly, deodorizing distillate was dehydrated by Na2SO4 and then free fatty acids in deodorizing distillate were converted to ethyl esters with concentrated H2SO4 catalyst and 20 ; 1 ethanol : deodorizing distillate ratio (mol/mol) at 700C for 80 minutes. Secondly, the product mixture of ethyl esterification reaction was evaporated, alcohol and acid removed by water washing. Ethyl esters of fatty acids were removed by vacuum distillation at 5mbar and at 198 - 2250C. Phytosterols were separated from distillation bottoms by crystallization method with etanol at 50C to obtain crude vitamin E. It was extracted with two times ethanol, then crystallized at -150C to remove remnant phytosterol and other undesired substances. Finally, natural vitamin E with 90.8% purity was extracted on silica gel (0.063 – 0.200 m) column with eluted solvents, n-hexan : ethanol: 9:1.