Optimization of phenolic compound recovery and antioxidant activity of light and dark dried fig (Ficus carica L.) varieties

The optimum conditions for extraction of total phenolic contents (TPC) and for enhancing the antioxidant activity from light and dark dried figs were determined. The effects of the solvent nature (acetone, ethanol, methanol, or water), solvent concentration (20–80%), acetic acid concentration (0–2%), extraction temperature (25–70°C), extraction time (0.5–4 h), sample to solvent ratio (1/25–1/100), and number of extractions (1, 2, and 3) were determined. The TPC was used to identify antioxidant compounds. 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used to evaluate antioxidant activity. All extraction parameters had significant effects (p<0.05) on the TPC and the antioxidant activities. The best conditions were obtained with double extraction using 60% acetone without acidification, at 40°C for 120 min, and with a 1/75 solid to solvent ratio. These conditions resulted in TPC concentrations of 469.46 (light variety) and 399.79 mg of gallic acid (GAE)/100 g (dark variety), and antioxidant activities of 96.47 and 102.28 mg of GAE/100 g, respectively.