Application of molecular distillation in the recovery of high-value bioactive compounds present in wastes of vegetable oil processing: effect of esterification

Refining vegetable oils generate residues that can be reused to obtain high-value compounds. Tocopherols, phytosterols, and squalene can be recovered from deodorizer distillates using molecular distillation. However, treatment of the deodorizer distillates is required to obtain better separation results. Thus, this work aimed to evaluate the effect of the esterification of a residue composed of mixtures of different types of deodorizer distillates on the efficiency of phytonutrient recovery by molecular distillation. The results showed the best conditions for the esterification were 74 °C, 214 min, 3% H2SO4, and 2:1 molar methanol/free fatty acids ratio. These reaction conditions maintained 97% of total phytonutrients and reduced 90.5% of free fatty acids. Concentration gains for tocopherols (331%), phytosterols (232%), and squalene (300%) were obtained for the esterified residue. Therefore, this work presents an alternative route to obtaining a phytonutrient concentrate by combining steps of esterification and molecular distillation for mixtures of deodorizer distillates.