In conclusion, the diversity of the extraction solvents
showed a significant effect on the profiles of bioactive
compounds of defatted marigold residue extracts. The antioxidant
activity of defatted marigold residue extracts was highly correlated with the content of polyphenols. On-line
HPLC–ABTS•+ and HPLC–DAD–MS analysis testified that
the antioxidant activity of the marigold extracts was mainly
induced by nine antioxidant compounds, of which quercetagetin
exhibited the most strong antioxidant capacity.