Enrichment of Minor Components -Carotenes, Tocochromanols - from Edible Oils

摘要

Enriching tocochromanols, in particular tocotrienols and carotenoids from its natural sources, e.g. palm oil, is possible using supercritical fluids Supercritical fluid extraction (SFE) offers several advantages over conventional techniques such as vacuum distillation. For the enrichment of tocochromanols crude palm oil (CPO) and distillates have been investigated, For the tocochromanol enrichment the entire concentration range is covered from concentrations in CPO to nearly pure isomers. The general procedure was as follows: Phase equilibrium measurements were conducted in order to obtain basic data in respect to gas load and distribution coefficient This data allowed the theoretical description of the separation process within the scope of a separation analysis, eventually yielding in optimum extraction conditions and column design parameters. The results were subsequently verified experimentally by employing a 6 m SFE column in pilot scale and a 5-stage mixer-settler. The results show that the tocochromanol enrichment with counter-current columns can well be extended beyond 70 wt-%. If the sterols are removed, even higher concentrations can be achieved. For the carotenoids, only the mixer-settler was used, resulting in a fraction containing about 10 wt-%, from which on further concentration can be achieved. The investigation revealed that above a level of about 50 % of tocochromanols the column separation gets increasingly difficult Therefore, an adsorption - desorption with supercritical fluids was carried out at different pressure levels By this procedure the tocochromanol content of the product could be enhanced to more than 85 %,. Further enrichment is possible with chromatographic techniques, useful for small quantities. Elution separation and simulated moving bed separation was applied and carried to purities in the range of 95 %.