Optimization of Different Extraction Methods of irradiated Chamomile on Antioxidant Activity and Chamazulene Content Using Response Surface Methodology

Abstract

This study successfully determined the optimal supercritical fluid (CO2) extraction (SFE) parameters for recovering high-potency antioxidants from irradiated chamomile (Matricaria recutita L.). Utilizing a Box–Behnken response surface design, the effects of pressure, temperature, and extraction time were modeled to maximize radical-scavenging activity. Determinations of antioxidant activities of chamomile oil samples were accomplished using 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2´- azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods The optimization identified distinct coordinates for peak performance: 257.17 bar, 50°C, and 180 min for DPPH (IC50 = 162.15 μg/mL), and 272.72 bar, 50°C, and 131.51 min for ABTS (IC50 = 85.55 μg/mL). Validation trials confirmed the model's high predictive accuracy. While SFE-derived oils and powders exhibited robust antioxidant activity, they remained slightly below synthetic standards. Furthermore, Gas Chromatography / Mass Spectroscopy (GC/MS) analysis identified key bioactives - including α- bisabolol oxides, (E)-β-farnesene, and chamazulene - in accordance with European Pharmacopoeia standards, noting that maximum chamazulene recovery (7.12%) required a 4-hour steam distillation.