Food and Public Health 2016, 6(6): 157-164 DOI: 10.5923/j.fph.20160606.02 Supercritical Extraction of Cobia (Rachycentron canadum) Liver Oil as a New Source of Squalene Débora Nascimento e Santos, Eliane Hissae Takahashi, Alessandra Barros Verde , Alessandra Lopes de Oliveira * Food Engineering Department, Faculty of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga, Brazil Abstract Cobia is a fish cultivated worldwide and there are few studies on the potential of their waste, such as the liver, it's rich in oil and active compounds. The objective of this study was to extract cobia liver oil (CLO) using supercritical CO 2 under moderate temperature conditions (50, 60 and 70 °C, 250 bar) and characterize the oil (physico-chemical analysis, fatty acids profile and squalene content). The results showed that CLO is rich in MUFA and presented squalene, suggesting that this matrix can be applied in the production of high nutritional value oil. Keywords Liver fish oil, Cobia, Supercritical extraction, Omega 3, Squalene 1. Introduction Cobia, Canadum Rachycentron, is a marine fish native to Brazil and found in tropical and subtropical seas. In captivity, this fish presents a high growth rate with low incidence of disease and produces high-quality meat [1, 2]. Because of these attributes, this species has been widely used in aquaculture in some countries in Asia and the Pacific region, generating a product of great economic value [3]. In Brazil, the production of cobia in captivity was initiated in 2006, and it continues in expansion due to encouragement from the Fishery Ministry and the private sector [4]. The cobia growing in captivity generated stimulus for studies about feeding and management techniques for growth efficiency. The world production of fish, including fishing and fish farming, was 158 million tons in 2012. Out of this total, 136.2 million tons (86% of total production) were used for human consumption, and the remaining 14% (21.7 million tons) was used for non-food purposes such as fishmeal and fish oil production [5]. Fish oil extraction can be classified into physical, chemical, and biological processes. The chemical extraction, realised with organic solvents, is a process well established. However, the use of toxic solvents can result in protein denaturation and loss of functional properties [6, 7]. In this context, supercritical fluid extraction is a potential alternative for the many advantages that it presents in relation to other methods. Supercritical fluid extraction using CO 2 as a solvent can be applied to obtain fish oil rich in unsaturated fatty acids at * Corresponding author: alelopes@usp.br (Alessandra Lopes de Oliveira) Published online at http://journal.sapub.org/fph Copyright © 2016 Scientific & Academic Publishing. All Rights Reserved low temperatures. Supercritical CO 2 extraction produces no oxygen in the process, which is responsible for the oxidation of fatty acids. The supercritical CO 2 density can be easily changed with temperature and pressure alteration, which modifies the solvating power of the solvent. Another known characteristic is the low toxicity of CO 2 that is recognised as safe (GRAS) and still produces clean waste extraction and solvent-free extracts [8, 9]. The first studies of the application of supercritical CO 2 extraction in fish oils were conducted in the 1950s. They studied the phase equilibrium data and compounds of the fish oils obtained by supercritical CO 2 and other organic solvents [10]. Some studies have shown the fractions purification of substances such as ethyl esters, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) [11], acid esters of fish oils [12], and contaminants [13]. In recent studies, supercritical extraction has been applied for new fish species or by-products [14] or as an extraction method combined with other processes such as molecular distillation [15] in order to optimise the fractionation of compounds with biological activity such as alkylglycerols and squalene. The objective of this research was to obtain cobia liver oil (CLO) using supercritical extraction in different operational conditions in order to characterise this oil by determining physico-chemical parameters and the fatty acid profile and by investigating the presence of bioactive compounds such as squalene. In addition to the study of clean technology to extract CLO, this study aimed to use waste from the fishing industry, such as raw material, for the production of oil with active properties. 2. Materials and Methods 2.1. Materials and Sample Characterisation