ASSESSMENT OF PHORBOL ESTERS CONTENT IN CRUDE OIL, OIL CAKE AND THE BRIQUETTES OF JATROPHA CURCAS L. IN MOZAMBIQUE

The expansion of the cultivation of Jatropha curcas L. is progressive and is in line with the need to use alternative sources of vegetable oil for biodiesel production. The use of oil cakes and briquettes of Jatropha curcas L. for thermal energy and animal feed would produce a necessary income and economically enable the cultivation of Jatropha curcas L. The oil and other by-products of Jatropha curcas have several toxic compounds, which should be well known, for reasons of public health. This work aims at to evaluate the phorbol ester contents in the crude oil, the oil cakes and the briquettes of Jatropha curcas L. in Mozambique. The crude oil and oil cake were extracted using the mechanical pressing method, at temperatures of 80-100°C preheating of the seeds for 20 minutes, in a mixer type creamer before extraction. The briquettes were produced at controlled temperatures of 125-185°C at pressure of 5-10MPa for 10 minutes each. The content of phorbol ester was evaluated using high-performance liquid chromatography (HPLC). Non-degummed crude oil presented a high level of phorbol esters content. The oil cake showed a lower content of phorbol esters of 0.96-0.63mg/g. Phorbol esters in the briquettes decreased with increasing the temperature during the production from 0.20 to 0.03mg/g at 125 to 175ºC and 5MPa and from 0.14 to 0.01mg/g at 125 to 165ºC and 10MPa, showing the influence of temperature and pressure on the phorbol esters content.