Flavonoid content and antioxidant capacity of spinach genotypes determined by high-performance liquid chromatography/mass spectrometry

BACKGROUND: Flavonoids in different spinach genotypes were separated, identified, and quantified by a high-performance liquid chromatographic method with photodiode array and mass spectrometric detection. The antioxidant capacities of the genotypes were also measured using two antioxidant assays–oxygen radical absorbance capacity (ORACFL) and photochemiluminescence (PCL)–which measure the response to the peroxyl and superoxide anion radicals, respectively. RESULTS: Eighteen flavonoids representing glucuronides and acylated diand triglycosides of methylated and methylene dioxide derivatives of 6-oxygenated flavonols were identified (patuletin, spinacetin, spinatoside, jaceidin). The total flavonoids ranged from 1805 to 3703 mg kg−1, indicating 2.0-fold variation among genotypes. The ORACFL and PCL values ranged from 48.7 to 84.4 mmol kg−1 and from 9.0 to 14.0 mmol kg−1, respectively, representing as much as 1.7-fold variation among genotypes. CONCLUSION: The ORACFL and PCL values were highly correlated with total flavonoid content (rxy = 0.96).  2008 Society of Chemical Industry