Supercritical carbon dioxide extraction of squalene rich cod liver oil: Optimization, characterization and functional properties

Abstract

Cod liver oil (CLO) was extracted using conventional hexane and pressing methods or ecofriendly supercritical carbon dioxide (SC-CO2). The extraction main parameters including temperature (A), pressure (B), and CO2 flow rate (C) were optimized using response surface methodology. The oil chemical composition, safety, thermostability, and biological properties were characterized. The optimized SC-CO2 extraction conditions were A = 49 °C, B = 29.9 MPa, and C = 4.97 mL/min. Time-dependent extraction curves revealed a 68%, 85%, and 89% CLO recovery in 5, 15, and 20 h, respectively. SC-CO2-extracted oil contained the highest squalene (≈150 µg/mL) and vitamins D and K concentrations and the lowest toxic heavy metal levels. Thermogravimetric analysis indicated that SC-CO2-extracted oil was more susceptible to thermal degradation because of its high purity. SC-CO2-extracted CLO exhibited radical scavenging and antimicrobial functions and was cytotoxic for cancer cells suggesting its potential use in the nutraceutical industry and novel functional material designs.