The extraction of carotenes from palm oil

This paper describes all improved method of carotene extraction from palm oil using locally produced activated carbons. The carbon fouled to be most efficient for carotene extraction is that from saw dust (5511). The UV spectrum of the carotene extract showed an absorption peak at 325 nm, which is associated with the oxidation of carotene. However, this absorption peak disappeared when the carbons were treated with alpha-tocopherol prior to extraction. Various conditions were studied to increase the extraction efficiency: The extraction can be carried out at ambient temperature (29°C) for olein or diluted crude palm oil. T1le suitable oil: carbon ratio was found to be within the range of 5: 1 to 10: 1. Toluene and p-xylene were found to be the two most effective solvent to free the adsorbed carotenes from the carbon surface. The activated carbon used for extraction could be recycled for carotene extraction as many as ten times, after which it could be regenerated for further extraction another ten times. It found that high moisture content in the carbon reduced the adsorption of carotene onto the surface, and also there was no increase in the recovery of carotenes from the carbon. impregnation of metabolism(viz. Ag+, Fe++ and Mg++)on to the carbon surface enhanced the adsorptive power, but the recovery of the adsorbed carotenes was low. Under optimum conditions, thecarotene extract from olein has a carotene concentration of 3916 ppm compared with 649 ppm in the original olein. This represents a six fold increase ill the carotene concentration. It has been found that the quality of the' oil, particularly in terms of free fatty acid content and totox value (2PV + A V) is improved after treatment with activated carbon. In a typical case, the free fatty acid content was reduced from 2.43% to 0.43% and the totox value from50.65 to 21.33. Based on feeding experiments using albino rats, the carotene extract was found to be biological(y active and safe for animal consumption. Preliminary absorption studies show that activated carbons with large specific surface areas and a large number of mesopores are suitable for carotene extraction. The pH of activated carbon found suitable for carotene extraction from palm oil/was around/d 10.8.