Supercritical carbon dioxide extraction of beta-carotene and alpha-tocopherol from pumpkin: a Box-Behnken design for extraction variables

In this study, supercritical fluid extraction with carbon dioxide was applied to achieve a successful extraction of both beta-carotene and alpha-tocopherol from pumpkin. To achieve the ideal optimization of this process, response surface methodology combined with a Box-Behnken design were used to thoroughly investigate the effect of extraction variables, such as pressure (20-30 MPa), temperature (40-50 degrees C) and the mass ratio of pumpkin flesh against pumpkin seed (0 : 1-2 : 1) on the yield of oil, alpha-tocopherol and beta-carotene from pumpkin. The results indicated that the mass ratio of pumpkin flesh against pumpkin seed significantly influenced the extraction of oil, alpha-tocopherol and beta-carotene. Three second-order polynomial mathematical models were determined for each response with high R-square values (>0.95) in the present experiment. The maximum yield of oil, alpha-tocopherol and beta-carotene was 14.20 +/- 0.80 g/100 g sample, 9.53 +/- 1.20 mg/100 g sample and 20.50 +/- 0.50 mg/100 g sample, respectively, corresponding to the extraction process under optimal conditions (i.e., pressure of 30 MPa, temperature of 47.75 degrees C and 67% of seed) using Derringer's desirability function method.