Carotenoids and flavonoids in organically grown spinach (Spinacia oleracea L) genotypes after deep frozen storage

After frozen storage the content of individual carotenoids and flavonoids was determined in organically grown spinach genotypes (Spinacia oleracea L) which differed in leaf colour and shape. The spinach was sorted, washed, blanched in steam for 3 min and frozen in liquid nitrogen. After frozen storage the green colour was determined by sensory evaluation and HunterLab colorimetry. The content of individual chlorophylls, carotenoids and flavonoids was determined using HPLC. Lutein, beta -carotene, violaxanthin and 9 '-(Z)-neoxanthin were the main carotenoids in processed spinach. The total content of carotenoids varied from 176.6 mg kg(-1) 'wet weight' as eaten in the lightest green genotype to 226.3 mg kg(-1) 'wet weight' as eaten in the darkest green genotype. The highest content of beta -carotene (83.1 mg kg(-1) 'wet weight' as eaten) was found in the dark green genotype. The content of lutein and neoxanthin varied significantly between genotypes, and the highest content was found in the dark green genotype (76.0 and 25.4 mg kg(-1) 'wet weight' as eaten respectively). The total flavonoid content and the relative content of individual flavonoids were found to vary between the six genotypes. Seven main flavonoids were identified. (C) 2001 Society of Chemical Industry.