Extraction and Identification of Water-Soluble Compounds in Palm-Pressed Fiber by SC-CO₂ and GC-MS

The residual oil recovered from palm-pressed fiber is known to contain high level of carotenes (4,000 mg kgˉ¹ to 6,000 mg kgˉ¹) and vitamin E such as tocopherols and tocotrienols (2,000 mg kgˉ¹ to 3,000 mg kgˉ¹). In this study, the water-soluble compounds in fresh palm-pressed fiber were recovered by supercritical carbon dioxide (SC-CO₂) extraction. The concentration of these compounds in palm-pressed fiber oil recovered was determined in the range of 1,000 mg kgˉ1 to 2,000 mg kgˉ¹. A total of 12 compounds have been identified from this water-soluble extract with molecular weights ranging from 126 amu. to 208 amu.. Preliminary results showed that these water-soluble compounds possess superior antioxidant properties screening using FRAP (Ferric Reducing Ability of Plasma) and TEAC (Trolox Equivalent Antioxidant Capacity) assays.