Extraction of oil and minor lipids from cold-press rapeseed cake with Supercritical CO 2

Abstract

This study examines the extraction of oil from cold-press rapeseed cake using Supercritical CO 2 (SC-CO 2). The effects of pressure (20, 30, and 40 MPa), temperature (40, 50, and 60°C), and extraction time (60, 90, and 120 min) on oil yield and composition (tocopherols and carotenoids) were studied using response surface design. The results indicated that pressure influenced the most the yield of oil, followed by temperature and extraction time. Extraction time had no effect on oil composition. Extraction pressure and temperature did not affect the tocopherol concentration of the oil to a great extent, whereas temperature had no affect in its carotenoid concentration. A comparison was made between the relative qualities of oil extracted with SC-CO 2 at 40 MPa and 60°C and with n-hexane. Neither solvent affected the unsaponifiable matter content or the composition of phytosterols (mainly β-sitosterol, campesterol and brassicasterol) of the oils, although there was a significant difference (p<0.05) in tocopherol. Extraction with SC-CO 2 at 40 MPa and 60°C is recommended to obtain rapeseed-oil enriched with tocopherols and carotenoids as important functional components.