A simple two-step method for simultaneous isolation of tocopherols and free phytosterols from soybean oil deodorizer distillate with high purity and recovery

Most of the methods reported for isolating phytosterols and tocopherols from soybean oil deodorization distillate (SODD) involved complicated steps or failed to obtain high content and recovery. In this study, we succeeded in isolating α-, δ-, γ-tocopherols, and free phytosterols (campesterol, stigmasterol, and β-sitosterol) from SODD with high content and recovery. Our protocol involved a simple two-step method. SODD was separated into non-polar and polar fraction by modified soxhlet extraction. Cold saponification was chosen instead of conventional saponification which is carried out at a temperature no lower than 60°C. This study of cold saponification was applied to the polar fraction to remove free fatty acids and acylglycerols. SODD contains 9.13±0.28% tocopherols and 9.75±0.12% free phytosterols, was converted to a final product which contains 38.08±0.36% tocopherols and 55.51±0.56% free phytosterols. The total recovery of tocopherols and free phytosterols is 94±0.19%.