Comparison of supercritical and near-critical carbon dioxide extraction of carotenoid enriched wheat bran oil

Abstract

Supercritical and near-critical carbon dioxide (CO₂) extraction were carried out to extract oil from wheat bran. The extraction temperatures for supercritical and near-critical CO2 were 35 - 45°C and 25 - 30°C, respectively. The applied pressure was ranging from 10 to 30 MPa for both supercritical and near-critical CO₂ extraction. The extraction was performed in a semi batch process with a CO₂ flow rate of 26.81 g/min for 1.5 h. The oil obtained from wheat bran at different extraction conditions was quantitatively measured to  investigate the solubility of oil at supercritical and near-critical CO2. The highest solubility was found at near-critical condition. The fatty acid compositions of wheat bran oil were measured by gas chromatography (GC). Linoleic, palmitic, oleic and γ-linolenic acid were the major fatty acids of wheat bran oil. Total carotenoid was measured spectrophotometerically. Highest yield of total carotenoid was found at 45°C and 30 MPa.

Key words: Supercritical and near-critical carbon dioxide, wheat bran oil, total carotenoid.