Supercritical SC-CO(2) and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis.

ABSTRACT

The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO(2)) and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO(2) extract (T = 40°C, P = 180 bar, time = 135 mn, CO(2) flow 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-CO(2) 57.60% (spiny), 59.98% (thornless), soxhlet n-hexane 57.54% (spiny), 60.66% (thornless), followed by oleic acid, SC-CO(2) 22.31% (spiny), 22.40% (thornless), soxhlet n-hexane 25.28% (spiny), 20.58% (thornless) and palmitic acid, SC-CO(2) 14.3% (spiny), 12.92% (thornless), soxhlet n-hexane 11.33% (spiny), 13.08% (thornless). The SC-CO(2) profiles fatty acids showed a richness with other minority compounds such as C(201), C(202), and C(22).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).