This study optimized the extraction of hesperidin and narirutin from immature Citrus unshiu pomace (ICUP) and evaluated their antioxidant activities. Response surface methodology determined optimal extraction conditions (80.3 °C, 58.4% ethanol, 40 mL/g solvent/feed, 30 min, two extractions). Ethanol proved a more effective solvent than methanol or acetone. The ethanol extract exhibited strong ROS scavenging activity but relatively lower activity against nitrogen radicals and RNS. Antioxidant activity correlated more strongly with hesperidin content than narirutin content. The optimized method shows promise for producing antioxidant-rich extracts for functional foods and nutraceuticals.

Dong-Shin Kim, Sang-Bin Lim