OPTIMIZATION OF THE AR-TURMERONE EXTRACTION FROM TURMERIC (Curcuma longa L.) USING SUPERCRITICAL CARBON DIOXIDE

Extracting volatile compounds using supercritical carbon dioxide (scCO2) is one of the most interesting applications of supercritical technology, due to the high solubility of these substances in scCO2. Supercritical carbon dioxide extraction (SFE-CO2) has been applied for obtaining extracts from several vegetable matrices, among them turmeric (Curcuma longa), because its volatile oil contains a target bioactive compound: ar-turmerone. However, the optimization of the SFE-CO2 operating conditions aiming to obtain ar-turmerone rich extract has not been studied yet. Therefore, applying supercritical technology for optimizing arturmerone extraction from C. longa L was the objective of this study. Turmeric rhizomes were ground, sieved and placed in contact with scCO2 flowing at 8.5×10 kg/min in a laboratorial-scale SFE unit. An experimental full factorial design composed of six levels of pressure (10, 15, 20, 25, 30 and 35 MPa) and three levels of temperature (313, 323 and 333 K) was carried out in duplicate for evaluating the global and ar-turmerone yields. From these assays, we selected three conditions (333K/25MPa, 333K/20MPa and 313K/20MPa) presenting higher yields to study the kinetics of the process. Major compounds in the extracts were identified and quantified by gas chromatography. Using SFE-CO2 led to high extract and ar-turmerone yields. Fost extraction combined with relatively low solvent consumption were observed. According to the spline model, solvent to feed mass ratio of only 0.94 would be required for extracting more than 90% of the ar-turmerone contained in the raw material at 333 K and 20 MPa. Thus, we suggested that this is a suitable condition for obtaining arturmerone.