Supercritical fluid extraction has emerged as an attractive separation technique for the food and pharmaceutical industries due to a growing demand for “natural” processes that do not introduce any residual organic chemicals. Supercritical carbon dioxideis by far the most commonly used supercritical fluid. The unique solvent properties of supercritical carbon dioxide have made it a desirable compound for separating antioxidants, pigments, flavors, fragrances, fatty acids, and essential oils from plant and animal materials. In the supercritical state, carbon dioxidebehaves as a lipophillic solvent and therefore, is able to extract most nonpolar solutes. Separation of the carbon dioxidefrom the extract is simple and nearly instantaneous. No solvent residue is left in the extract as would be typical with organic solvent extraction. Unlike liquid solvents, the solvating power of supercritical carbon dioxidecan be easily adjusted by slight changes in the temperature and pressure, making it possible to extract particular compounds of interest. With the addition of small amounts of polar co-solvents, even polar materials can be extracted. Additional advantages of carbon dioxide are that it is inexpensive, it is available in high purity, it is FDA approved, and it is generally regarded as a safe compound (GRAS). Supercritical carbon dioxideis also desirable for extraction of compounds that are sensitive to extreme conditions because it has a relatively low critical temperature (31°C).