Enhancing the separation and purification efficiency of palm oil carotenes using supercritical fluid chromatography

Palm oil is the richest source of natural plant carotenoids in terms of retinol or pro vitamin A equivalent. The carotenoids found in palm oil consist of carotenes and xanthophylls, with about 500 to 700 ppm carotenes in crude palm oil. Effort has been made to extract and recover the valuable carotenes from palm oil, where they are being made into nutritional supplements or as ingredients in cosmetics formulations. This article reports on the application of supercritical fluid chromatography (SFC) for such purpose. While SFC has been conventionally used as an analytical tool, its application in preparative or even pilot scale has been gaining popularity of late. The process and feasibility of extraction and recovery of carotenes from palm using SFC are reported whereby it was found that the SFC is able to purify the palm carotenes in consistent purity and production rate with no effect on the processing time. Carotenes were obtained in one chromatographic step with SFC, using carbon dioxide as the mobile phase and ethanol as modifier at 60oC and 190 bar. The purity of the end product and production rate however, can be greatly enhanced with the introduction of a pre-treatment step, prior to the purification by SFC. The purity of the end product increased by more than four-fold with the introduction of the pre-treatment step. The technical and economical feasibility of the purification of carotenes from palm, including the pre-treatment process, were studied and discussed in this article