Producing antioxidant fractions from herbaceous matrices by supercritical fluid extraction

Fractions from seeds of coriander (Coriandrum sativum) were obtained by extraction with supercritical carbon dioxide in a semicontinuous lab-scale equipment, and were tested for their antioxidant activity. Initially, the essential oil was removed from the herbal material by extraction with low density (0.60 g/ml) CO2. Then the seeds were further extracted with high density (0.73-0.83 g/ml) CO2 at pressures from 116 to 280 bar and temperatures from 311 to 331 K. The antioxidant activity of the fractions was determined by measuring their ability to remove the free radicals present in a methanol solution of 1, 1 -diphenyl-2-pierylhydrazyl (DPPH). The extracts exhibited a significant activity, comparable to that of commercial antioxidants. These results indicate that supercritical extraction is a promising processing alternative for producing odorless and tasteless antioxidant fractions from coriander seeds. (C) 2002 Elsevier Science B.V. All rights reserved.