Optimization of Satureja montana subcritical water extraction process and chemical characterization of volatile fraction of extracts

The objective of this study was to assess the effects of different extraction parameters on Satureja montana subcritical water extraction process, in terms of total phenols, total flavonoids and antioxidant activity of extracts (expressed as IC50 value) by employing response surface methodology. The most efficient extraction conditions for all three responses were temperature of 200 degrees C and extraction time of 20.8 min. The values of total phenols, total flavonoids, and IC50 obtained by applying these operating parameters were found to be 11.24g GAE/100 g, 6.84g CAT/100 g and 0.0028 mg/mL, respectively. These predicted data were experimentally confirmed with a deviation of +/- 5%. Chemical characterization of volatile fraction of extracts was carried out by GC-MS analysis and carvacrol was determined as the most dominant volatile component in all of the extracts. The presence of thymoquinone, an oxygenated monoterpene with a highly significant biological activity, was established. (C) 2016 Elsevier B.V. All rights reserved.