Recovery of phytosterols from waste residue of soybean oil deodorizer distillate.

This study describes a catalytic decomposition and crystallization process to recover phytosterols from the waste residue of soybean oil deodorizer distillate (WRSODD). Various solvents were used for the crystallization of phytosterols. The effect of different solvents on the purity and yield of recovered phytosterols was investigated. The composition of WRSODD was analyzed by silica gel column chromatography and FT-IR spectrum. Gas chromatography (GC), GC-MS, and FT-IR were adopted to determine the purity and structure of phytosterols. Results showed the total amount of phytosterols, in the form of fatty acid steryl esters, was up to 20 wt.% of WRSODD. Through orthogonal experiments, the optimized crystallization conditions were obtained. It's found the mixed solvent of acetone and ethanol (4/1, v/v) could generate good crystallization. The yield of recovered phytosterols was 22.95 wt.% after the 1st crystallization. The purity of phytosterols reached 91.82, 92.73, and 97.17 wt.% after the 1st, 2nd, and 3rd crystallization, respectively.