Abstract: Response surface methodology was used to optimize conditions for the supercritical fluid extraction with carbon dioxide of β-carotene from watermelon bee pollen, and crude β-carotene extract was tested for antioxidant activity. The optimal conditions for β-carotene extraction were found to be extraction at 51 ℃ and 34 MPa for 80 min. Under these conditions, the extraction yield of β-carotene was 8.79 mg/100 g. The resulting extract had stronger scavenging activity against ABTS free radials than Trolox and β-carotene standard. Moreover, its total reducing power and DPPH radical scavenging activity were higher than those of β-carotene standard but weaker than those of Trolox.

Key words: β-carotene, supercritical fluid extraction, antioxidant activity