Lipids from <i>Vitellaria paradoxa</i> Gaertn Seeds by Supercritical CO₂: Extraction and Optimization of Parameters by Response Surface Methodology

Abstract

Supercritical carbon dioxide (CO₂) was employed to extract lipids from Vitellaria paradoxa Gaertn seeds in semi–batch process at various operating conditions to optimize extraction process. The extraction processes were carried out at 40 – 60 ^oC and 20 – 40 MPa with 2 – 4 ml min^–1 CO₂ flow rates. Analysis of variance (ANOVA) with 33 factorial design combined with statistical was used to optimize variables in the process of Vitellaria paradoxa Gaertn seeds lipids extraction with supercritical CO₂. The FT–IR spectra indicated that the Vitellaria paradoxa Gaertn seeds components were extracted by supercritical CO₂. The SEM images also indicated that the physical changes in the surface of the Vitellaria paradoxa Gaertn seeds occurred after supercritical CO₂ extraction treatment. The maximum of extracted lipids was 0.47 g/g–sample when the extraction was conducted at a temperature of 80 ^oC and pressure of 40 MPa with CO₂ flow rate of 3 ml min^–1. The GC–MS analysis showed that the extracted lipids mainly composed of palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). The analysis of experimental design demonstrated that pressure and temperature were the influential variables on the lipids extraction.