Oxidative Susceptibility and Thermal Properties of Moringa Oliefera Seed Oil Obtained by Pilot Scale Subcritical and Supercritical Carbon Dioxide Extraction
Oxidative stability, antioxidant activity and thermal properties of Moringa oleifera (MO) seed oil obtained by supercritical carbon dioxide (SC CO2) extraction were studied in comparison with Soxhlet extraction. CO2 was used to extract the oil in the pressure ranges from 15 to 40 MPa and the temperature ranges from 25 to 35C at 20 kg/h flow rate. SC CO2 extraction at 35 MPa and moderate temperature of 30C resulted in the maximum relative oil yield of 75.27% (dry basis) Susceptibility to oxidation of MO seed oil was expressed as the oxidative stability index (OSI) The results indicated that MO seed oil extracted at higher pressure was less susceptible to oxidation. The oil obtained by Soxhlet extraction was significantly (P 0.05) more stable against oxidation compared with SC CO2 extracted oils as shown by its stronger DPPH (1,1 diphenyl 2 picrylhydrazy) scavenging ability and higher OSI. The thermal properties of oil samples from SC CO2 extraction were not substantially different from those of oils extracted using Soxhlet extraction. Practical Applications Moringa oleifera (MO) seed has gained importance over the years due to its ultimate source of high quality oil that can be used in high value food, cosmetic and pharmaceutical products. However, MO seed oil has never been successfully produced on the industrial basis. This research proposed an alternative oil extraction from MO seeds using a pilot scale supercritical fluid extraction (SFE) SFE is considered as a green technology that is nontoxic and allows the elimination of polluting organic solvents. Only few scientific studies on the pilot scale SC CO2 extraction of MO seed oil and its stability against oxidation and thermal properties for uses as the new source of edible, healthy oil have been reported. Therefore, it is the objective of this study to know the oxidative susceptibility of MO seed oils extracted using SC CO2 in comparison with Soxhlet extraction.