Comparison of Phenolic Compound, Colour Value, and Antioxidant Activity of Roselle Calyces Extract Between Modified Supercritical Carbon Dioxide and Conventional Extraction

Supercritical carbon dioxide (SC-CO2) is a clean and green technology for extracting polyphenols antioxidants from roselle (Hibiscus Sabdariffa) as nutraceutical ingredients high-value co-products development. To increase the SC-CO2 fluid affinity towards polar compounds, general regard safe (GRAS) solvent, ethanol-water was added in small amount modifier. Dry calyces were extracted using modified conventional methods (Soxhlet Shaking Water Bath) to determine whether may improve extraction of phenolic content antioxidant activity. The results showed that extract had significantly higher yield total flavonoid than method. method produces redder but lighter extraction. also activity measured by DPPH radical scavenging. These suggest increases quantity quality calyces’ extract. findings increased reliability this technique produce products plant. Roselle low-cost sustainable local crop source, well energy process with low environmental impact, excellent solvent recyclability, reduced chemical use, could market value antioxidant-rich