Supercritical carbon dioxide extraction of oil from Thunnus tonggol head by optimization of process parameters using response surface methodology

Total oil was extracted from ground fish head of Longtail tuna (Thunnus tonggol) using supercritical carbon dioxide (SC-CO2) at 20 to 40 MPa, 45 to 65 °C and 1 to 3 ml min−1. Response surface methodology (RSM) was employed to optimize the operating conditions of the SC-CO2 technique where the highest oil yield was obtained (35.6% on dry weight basis) at 40 MPa, 65 °C, and 3 ml min−1. The solubility of the oil in SC-CO2 increased from 2.9 to 14.2 g oil/100 g of CO2 with increasing pressure and temperature. The total saturated, monounsaturated and polyunsaturated fatty acids obtained were 41.6, 24.7 and 26.8%, respectively, where the omega-3 fatty acids were found to be 22.3%. A correlation was developed determining the coefficients of the second-order polynomial equation where the extraction parameters of SC-CO2 method to extract fish oil from fish sample were successfully optimized using response surface methodology.