Sunflower oil from enzymatic aqueous extraction process: Maximization of free oil yield and oil characterization

Abstract

AbstractIn this article, the enzymatic aqueous extraction (EAE) of sunflower seed oil was investigated. The effects of the operational variables (temperature, water seed mass ratio, and enzyme concentration) were evaluated in order to define the conditions that maximize the free oil yield (FOY). It was observed that increasing the amounts of water and enzyme in the extraction medium was disadvantageous to the removal of the oil, and that an increase in temperature provided a higher FOY. Thus, a temperature of 60°C, seed:water ratio of 1:5 (g/g), and enzyme concentration of 1% (v/v) were defined as the conditions for maximum FOY (17.76%). The use of a buffered medium under these conditions increased the FOY to 20.34%. The composition of the oils obtained by the EAE under different experimental conditions was determined and compared with the oil obtained from Soxhlet extraction. The oils under study presented high levels of oleic and linoleic acids, which corresponded to ~90% of the composition of fatty acids. It was also noted that, depending on the extraction conditions, the oils obtained by EAE presented phytosterol and tocopherol contents similar or superior to those of the oil produced by Soxhlet extraction.Practical ApplicationsThe enzymatic aqueous extraction of sunflower oil has the potential to replace the solvent extraction method. The results reported herein show that the composition of the sunflower oil obtained by the enzymatic method was similar to that of the oil extracted by the solvent method. In addition, the enzymatic method uses mild conditions that reduce the energy required for the process and the residues are free of organic solvent.