Investigation of conversion of sunflower oil production wastes to high value compounds by supercritical CO2

Abstract

The evaluation of wastes from edible oil production industry has increasing importance because of resources deficiency and growing population day by day. It was aimed to investigate the recovery potential of oil and valuable components from sunflower oil production wastes by using supercritical CO2(SC-CO2) extraction as a green extraction method. In this context oil amounts, total phenolic content (TPC), total flavonoid content and antioxidant activities were analyzed. The waste samples obtained from filtration processes of the oil which were composed of oily bentonite (OB) and waxy perlite (WP). Soxhlet extraction was also applied on the waste samples to calculate extraction efficiencies of the SC-CO2. It was observed that SC- CO2extraction was more effective for OB (27%, v/v) than WP (11%, v/v). In addition, the efficiency increased to 37% by mixing expanded perlite and OB sample to absorb moisture content of the waste and to increase the diffusion of carbon dioxide more easily. The statistical evaluation of the experiments was also conducted to determine the effect of independent variables on the recovery efficiencys. Pressure was detected more effective variables on the recovery values than temperature. The maximum recovery efficiencies of the oil and TPC were obtained at the 50 °C, 22.1 MPa and 60 °C, 20 MPa, respectively.