Extraction of Tocopherol from Soybean Oil Deodorizer Distillate by Deep Eutectic Solvents

: Natural tocopherols have strong antioxidant and physiological functions, which are mainly produced from vegetable oil deodorized distillates. In this work, a simple and green solvent extraction method based on deep eutectic solvent has been developed to simultaneously extract three isomers of tocopherols (α, γ and δ-tocopherols) from soybean oil deodorizer distillate (SODD). The key factor to affect the solvent extraction efficiency was proposed that phenolic deep eutectic solvents interacted with targeted tocopherols mainly through π-π bonds interaction. This sustainable extraction process included two steps. Firstly, total tocopherols were extracted from SODD at room temperature by phenolic deep eutectic solvent composed of ChCl and p-cresol. Subsequently, tocopherols were successfully separated from deep eutectic solvent phase by re-extraction with n-hexane, and tocopherols products could be simply recovered. Under the optimum extraction conditions, the extraction efficiency of total tocopherols (α, γ and δ-tocopherols) from SODD was 77.6% after extraction with phenolic deep eutectic solvent.