The aim of this study was to compare the antioxidant activities and functional contents of Korean conventional and Chinese seed gingers from the Jeollabuk-do Wanju and Chungcheongnam-do Seosan regions. Ginger samples were subjected to steaming treatments for different durations (2–8 h) at 121oC using an autoclave. The antioxidant activity was evaluated by measuring total polyphenol and flavonoid contents and ABTS and DPPH radical scavenging activities, while functional ingredient contents were analyzed for gingerols and shogaols. The results showed that Wanju conventional seed ginger (WO-2) had the highest total polyphenol (85.24 mg GAE/g) and flavonoid (98.14 RE/100 g) contents, surpassing that of the control in all steamed groups at 6 h. ABTS radical scavenging activity showed a strong correlation with total polyphenol and flavonoid contents. The control groups indicated that Korean conventional seed ginger had 1.0–1.3 times higher gingerol contents compared to Chinese seed ginger. Furthermore, the content of shogaols, considered major functional ingredients, increased significantly with longer steaming durations, reaching the highest content (1,793 mg/kg) at 8 h, which was 1.0–1.8 times higher in Korean conventional seed ginger than that in Chinese seed ginger. These experiments provide valuable data supporting the excellence of Korean conventional seed ginger in the future.

Decolorization of congo red, rhodamine B was investigated by the white rot fungus Irpex lacteus which has biodegrading capability of various recalcitrants. White rot fungus Irpex lacteus is immobilized by PVA-freezing method. An immobilized Irpex lacteus decolorizes 91% of congo red in 8 days under culture with glucose 2%(initial conc.). It also showed 70% of decolorization at 3 days in the state of putting MnSO4 1mM. But, rhodamine B has no significant differences about decolorization among different mixture ratio of Irpex lacteus with PVA, concentration of carbon, nitrogen and manganese sulfate.