To determine antioxidant effect of emulsive β-carotene purified from R. babjevae JI-1, its free radical-scavenging capacity was measured with 1 mM of 2,2-diphenyl-1-picrylhydrazyl (DPPH) ethanol solution (200 µL) and β-carotene hexane solution (50 µL). The scavenging activity on hydroxyl radicals was calculated using the following equation: