Supercritical SC-CO2and Soxhletn-Hexane Extract of TunisianOpuntia ficus indicaSeeds and Fatty Acids Analysis

Abstract

The fatty acids profiles of TunisianOpuntia ficus indicaseeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO2) and soxhletn-hexane extract were compared. Quantitatively, the better yield was obtained through soxhletn-hexane: 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO2extract (T = 40°C,P=180bar, time = 135 mn, CO2flow rate = 15 mL·s−1). Qualitatively, the main fatty acids components were the same for the two types of extraction. Linoleic acid was the major compound, SC-CO2: 57.60% (spiny), 59.98% (thornless), soxhletn-hexane: 57.54% (spiny), 60.66% (thornless), followed by oleic acid, SC-CO2: 22.31% (spiny), 22.40% (thornless), soxhletn-hexane: 25.28% (spiny), 20.58% (thornless) and palmitic acid, SC-CO2: 14.3% (spiny), 12.92% (thornless), soxhletn-hexane: 11.33% (spiny), 13.08% (thornless). The SC-CO2profiles fatty acids showed a richness with other minority compounds such as C20:1, C20:2, and C22.The seeds oil was highly unsaturated (US = 4.44–5.25), and the rising temperatures donot affect the selectivity of fatty acids extract by SC-CO2: US = 4.44 (T = 40°C) and 4.13 (T = 70°C).