Supercritical carbon dioxide extraction of Dimorphotheca pluvialis oil seeds

The possibility of extraction of Dimorphotheca oil with supercritical carbon dioxide is demonstrated in this article. Before extraction, the seeds have to be pretreated to improve extraction yield. Experiments showed that the best pretreatment procedure for Dimorphotheca was heating the seeds under reduced pressure to 100 degrees C for 60 min, followed by flaking or milling. To give an impression about the efficiency of the supercritical extraction, a mathematical model has been developed to estimate the overall mass transfer coefficient (A(p)K). Also, an empirical relation between A(p)K and the interstitial velocity has been found. The physical properties of the supercritical Dimorphotheca oil are in good agreement with those of conventionally extracted oil, except for a lower phospholipid content. It is expected that further refining of supercritical Dimorphotheca oil will be marginal.