Submitted to: Industrial Crops and Products International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/15/2002
Publication Date: 11/8/2001
Citation: HOLSER, R.A., BOST, G. HIGH-PRESSURE EXTRACTION OF NATIVE HIBISCUS OILSEEDS. INDUSTRIAL CROPS AND PRODUCTS INTERNATIONAL CONFERENCE PROCEEDINGS. 2001. Interpretive Summary:
Technical Abstract: The seeds of native Hibiscus species contain a variety of phytochemicals with potential applications in functional foods, natural, and specialty products. Triglycerides, phospholipids, and sterols, for example, are conventionally extracted from oilseeds by organic solvents and subsequently recovered during a multi-step refining process. The rapid and efficient recovery of such compounds without organic solvents would improve the marketability of these compounds and promote the development of native Hibiscus as an alternative crop. Pressurized extraction techniques using water or carbon dioxide in place of organic solvents have demonstrated promise for the separation of hydrophilic and lipophilic compounds from oilseeds. Solvent density and dielectric show significant dependence on pressure near the critical point and may be be controlled to obtain greater selectivity in extractions. Hibiscus seed samples were reduced to 0.1-mm diameter particle size and subjected to a series of extractions performed with sub-critical carbon dioxide, super- critical carbon dioxide, super-critical water, and sub-critical water. Extracts were collected and characterized by standard analytical methods (GC-FID, GC-MS, HPLC) for the identification of major extractable components. The analytical results indicated that manipulation of both temperature and pressure could extend the solvating power of both solvent systems to achieve recoveries of predominately nonpolar components, e.g., triglycerides, and polar components. Pressurized extraction techniques provide a rapid method to separate a range of both polar and nonpolar natural products from Hibiscus seeds with environmentally benign solvents.