Recovery of γ-oryzanol from rice bran oil byproduct using supercritical fluid extraction

The residue of fatty acids distillation from rice bran oil soapstock (RFAD-RBOS) is a byproduct from rice bran oil industry. It contains a large amount of γ-oryzanol, which is a valuable antioxidant. The main objective of this work was to investigate the recovery of γ-oryzanol from the RFAD-RBOS using supercritical fluid extraction (SFE). The Soxhlet technique was conducted in order to compare results with SFE. The influence of process parameters over SFE was evaluated in terms of global yield, γ-oryzanol content, γ-oryzanol recovery rate, and fatty acids composition. The mathematical modeling of SFE overall extraction curve (OEC) was also investigated. The condition of 30 MPa/303 K presented the maximum global yield (39 ± 1%, w/w), maximum γ-oryzanol recovery rate (31.3%, w/w), relatively high γ-oryzanol content (3.2%, w/w), and significant presence of monounsaturated and polyunsaturated fatty acids. The logistic model presented the best fit to experimental OEC.