Effect of Process Parameters on Oil Yield in Process Optimization for Extraction of Essential Fatty Acid from Fish Using Solvent Extraction

Abstract

Fish oil is the fraction of lipid which is extracted from fish and its waste products. It is mainly composed of SFA, MUFA and PUFAs. PUFAs like omega-3, omega-6, ALA are long chain fatty acids (PUFAs) and is rated very highly, due to its active role in the prevention of many diseases. Extraction of fish oil is carried out by leaching process where solvent extracts the desired solute and is later is separated. The extraction process is affected by leaching temperature and time which is reflected in terms of yielding of oil. Therefore, this research work was undertaken to study the effect of solvent (hexane and isopropanol) mixture along with operating temperature and time and subsequently to optimize the taken parameters on the basis of oil yield. Experiments were conducted using Box-Behnken design with three variables at three levels having equal intervals. Variables selected for the experiment were extraction temperature (70, 80, 90°C), extraction time (5, 6, 7 h) and solvent ratio (hexane: isopropanol) (1:2, 1:1, 3:2). Responses selected were oil yield (%), acid value (mg KOH/g) and peroxide value (meq/kg). The data from all the experiments were analysed using design expert software version 9.0.6.2 and functions for responses were developed using multiple regression analysis and the second-order model was fitted for each response. It was observed that time and temperature had a highly significant impact on oil yield. With the increase in the level of both parameters, yielding of oil also increased. The results obtained were optimized using RSM. Optimum levels of variables were 82.0°C, 5 h and 0.5with oil yield value 71.1%.