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Jatropha curcas L. has biological activities that can contribute to find new products. In this study, steam distillation at laboratory scale was applied to J. curcas leaves to assess the yield of essential oil and the bioactivity of the hydrolate. The effect of steam flow and bed porosity on the extraction yield was also determined, where it was observed that residence time was one of the influential factors in the yield of essential oil. The extracts were analyzed by GC-MS. Dibutyl phthalate, phytol, and diisooctyl phthalate were the majoritarian components. Research reports indicate that these components have biological activity. The greatest yield obtained was 0.38% on a dry weight basis. The bioassays showed that the hydrolate of J. curcas possessed toxicity against Spodoptera littoralis, Myzus persicae, Lactuca sativa, and Lolium perenne. The bioactivity of these products should be further explored, they have a promising future as a biocontroller.

This study reports the extraction of Jatropha curcas leaves using supercritical CO 2. Experiments were performed varying the pressure (13 and 20 MPa) and the temperature (50˚C and 60˚C). The model of Sovová for supercritical fluid extraction was fitted to the experimental kinetic extraction curves. Two cell sizes were used and scale up equations compared. GC analysis showed phytol, carvacrol, and hexahydrofarnesyl acetone as major compounds in all the experiments. A maximum yield of 0.95% dry-weight basis was obtained. It was observed a maximum yield (0.95% dry-weight basis) extract obtained at 20 MPa and 50˚C. The results indicated that the mass yield increased with the increase of pressure. The bioassays showed that the extract of J. curcas possessed toxicity against Hyalomma lusitanicum.

Theory and concepts of boundary layer mass transfer is applied to correlate experimental data on extraction of essential oils from vegetable leaves and stems, using steam. From these theory, concepts and experimental data with seven systems, two correlations are developed to predict the Sherwood number and mass transfer coefficient as function of Reynolds and Schmidt numbers. From these equations, the molar flux, the amount of solute extracted, and the yield of extraction is predicted. A steam of higher temperature normally improves the mass transfer and the yield. A method to estimate the enhancement for temperature increase is proposed. The correlations developed are applied to a case with industrial size that was no part of the data for correlation generation. Theory may be applied for industrial applications.