A one-pot process for the extraction of fats and essential oil from coriander seeds by supercritical CO2

Abstract

International audienceThe seeds of coriander (Coriandrum sativum) are rich in vegetal oil (VO) and in essential oil (EO), which have both an interesting potential for the food, pharmaceutical and cosmetic industries. The review of the literature shows that most of the research works related to the extraction of coriander seeds are aimed at extracting either the VO or the EO. The aim of this work is to develop a process that can extract selectively the VO and EO in a consecutive way by tuning experimental conditions. A 4-step process has been set up: (i) seeds preparation by grinding and sieving, (ii) extraction by supercritical CO 2 (SC CO 2) and (iii; iv) selective separation in two separators with different pressure level. The first part of this study consisted in studying the effects of the operating conditions (T, P, CO 2 density, flow rate and particle size distribution of ground seeds) on the yield of extraction. The results showed that the global performance of the process depended mainly on the pressure level, on the CO 2 flow rate and on the size of ground seeds. An optimization of the parameters gave an extraction efficiency of 90 %. The second part of this study dealt with the effects of operating conditions on the quality of extracts, and more precisely on their composition in VO and EO. It was observed that the supercritical extraction had no major effect on the fatty acid composition of the VO compared to classical extraction procedures, while EO is enriched in components such as linalol and that a previous drying of the seeds is deleterious. Finally, we proposed a protocol in order to extract separately VO and EO by tuning CO 2 density and separation conditions