Iranian Chemical Science and Technologies Association International Journal of New Chemistry 2645-7237 12 5 2025 04 01 Response Surface Methodology Applied to the Supercritical Carbon Dioxide Extraction of Zingiber officinale Oleoresin 972 994 722671 10.22034/ijnc.2025.722671 EN Shahin Ahmadi Department of Pharmaceutical Chemistry, Tehran medical sciences, Islamic Azad University, Tehran, Iran. Sedighe Pardis Kian Department of Chemistry, Safadasht Branch, Islamic Azad University, Tehran, Iran Maryam Moghaddas Department of Chemistry, Safadasht Branch, Islamic Azad University, Tehran, Iran Journal Article 2025 04 10 <span style="font-size: 11.0pt; line-height: 150%; font-weight: normal;">This study explores the extraction of oleoresin from the rhizome of ginger (Zingiber officinale) using supercritical carbon dioxide (SC-CO₂) extraction and Soxhlet extraction techniques. Key operational parameters for SC-CO₂ extraction, including pressure (10–20 MPa), temperature (35–45 °C), and flow rate (10–16 g min⁻¹), were optimized to evaluate their influence on extraction yield, radical scavenging activity, and total phenolic content. A Box–Behnken design was employed for experimental design and analysis. Regression analysis confirmed that the experimental data conformed well to both linear and second-order polynomial models. The SC-CO₂ method achieved a maximum oleoresin yield of 6.47 ± 0.07%, significantly higher than the 3.19 ± 0.22% obtained using Soxhlet extraction. The antioxidant potential of the extracts, determined through 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, revealed values of 50.70 ± 0.52% for SC-CO₂ extraction and 88.50 ± 0.18% for Soxhlet extraction. The total phenolic content, quantified via the Folin–Ciocalteu method, was 103.24 ± 1.58% for SC-CO₂ extracts under optimal conditions, compared to 31.10 ± 0.28% for Soxhlet extracts.</span> https://www.ijnc.ir/article_722671_1ad0660f7d195c2dc50b52768a39fb2a.pdf