The presence of antioxidants can hinder the extent of β-carotene bleaching by acting on the
hydroperoxides formed in the system . The degradation rate of β-carotene-linoleate depends on the
antioxidant activity of the extracts, and the extracts with the lowest β-carotene degradation rate
exhibited the highest antioxidant activity. As shown in Table 1, the oxidation rate ratio (ROR) of the
crude extract and its derived soluble fractions from the flowers of C. sinica were 0.52 ± 0.005 (crude
extract), 0.58 ± 0.006 (petroleum ether fraction), 0.26 ± 0.004 (EtOAc fraction), 0.41 ± 0.005 (BuOH
fraction) and 0.51 ± 0.005 (water fraction). Their antioxidant activities (AA%) followed the order of
EtOAc fraction>BuOH fraction>crude extract ≈ water fraction> petroleum ether fraction.