Supercritical CO2 Extraction of Phenolic Compounds in Roselle (Hibiscus sabdariffa L.)

The extraction of phenolic compounds from roselle using supercritical CO2 was studied. The supercritical fluid extraction experiments were conducted at a range of pressures from 10 to 24 MPa and temperatures of 323.15, 333.15, and 343.15 K. The extraction time was 2.5 h. Three density-based equations, Chrastil, del Valle and Aguilera, and Mendez-Santiago and Teja, were used to correlate the experimental data. All three equations correlate with the actual the data quite well. The maximum yield obtained from the supercritical extraction experiment was 8.63 mg GAE=g dried rosella at 343.15 K and 24 MPa