Abstract: Ultrasound-assisted extraction and subsequent MgO column chromatography was used to purifyβ-carotene from elenium-enriched wheat seedling. The quantitative analysis ofβ-carotene was performed using high performance liquid chromatography (HPLC). Using orthogonal array design method, the optimal process parameters for ultrasound-assisted extraction of carotenoids from wheat seedling were petroleum ether-acetone mixture with a ratio of 95:5 (V/V) as the extraction solvent at a material/liquid ratio of 1:50 for triple repeated extraction at room temperature under the assistance of 300 W ultrasound power for 50 min each time. Under the optimal extraction conditions, the yield of carotenoids andβ-carotene from wheat seedling were up to 12.85 mg/g and 4.86 mg/g, respectively. Multiple adsorption peaks of the obtained extract were observed at 447 nm, which suggested that the composition of pigments in wheat seedling was complicated. The recovery ofβ-carotene was 93.37% after purification by MgO column chromatography. The purifiedβ-carotene presented an absorption peak at the retention times of 17.138 min and 16.726 min, respectively, suggesting the possible presence of some compounds with similar chemical structures.

Key words: wheat seedling, β-carotene, ultrasound, high performance liquid chromatography (HPLC)