Supercritical CO 2 Extraction of β‐Carotene from Sweet Potatoes

Using supercritical CO 2 to extract β‐carotene there was approximately a five‐fold or a three‐fold increase in amount of carotenoids extracted from freeze‐dried tissue relative to the amount extracted from oven‐dried or fresh tissue, respectively. The most efficient conditions were at 48°C and 41.4 MPa. Of the total carotenoid content ∼20% was inaccessible to supercritical CO 2 . The HPLC carotenoid profile of sweet potatoes showed that the unextracted tissue contained 90%β‐carotene, primarily as all‐trans (ca. 99%). Supercritical CO 2 extracts contained up to 94%β‐carotene. The isomer composition of β‐carotene of supercritical extracts showed ∼ 14% 13‐ cis and 11% 9‐ cis .