Study of the influence of process parameters on liquid andsupercritical CO2 extraction of oil from rendered materials: fish meal and oil characterization

Abstract

tLiquid and supercritical CO2has been used to extract the remaining fat content from rendered fish meal.The effect of pressure (10–40 MPa) and temperature (25–80◦C) on the extraction kinetics and extractionyield has been investigated as well as the effect on the rendered fish meal. The extraction curves areinitially linear with a slope close to the oil solubility value in pressurized CO2. Based on previous fishoil solubility data reported in the literature, a general equation has been proposed to correlate fish oilsolubility data as a function of temperature and density of CO2. Fish meal has been characterized beforeand after extraction by determining the fat and protein content and its colour. Toxic trace elements havebeen also determined by ICP-MS in the fish meal showing that most of the toxic elements remained inthe fish meal after extraction. Characterization of extracted oil was also performed by determining thefatty acid group composition and some physical parameters such as colour