Antioxidant anthocyanins screening through spectrum–effect relationships and DPPH-HPLC-DAD analysis on nine cultivars of introduced rabbiteye blueberry in China

Blueberries have drawn growing attention in China for various benefits to health. Nine rabbiteye blueberry cultivars which were introduced into China were systematically assessed based on two aspects of chemical profiles and antioxidant activity. The former was achieved by HPLC fingerprints, and the latter in terms of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging capacity was evaluated with a novel HPLC method. Subsequently, the predominant active anthocyanins were screened from these coloured biological samples by two useful methods, respectively. In method I, the spectrum–effect relationships between HPLC fingerprints and the antioxidant activities of blueberry extracts were investigated, whereas in method II, HPLC analysis followed pre-column reaction of samples with DPPH. The results indicated that Gardenblue and Powderblue showed stronger antioxidant activities among all introduced cultivars, and delphinins and anthocyanidin-3-glucosides were the main contributive components to the antioxidant activities of blueberries. This would be helpful to the quality-oriented cultivation of blueberry in China.