Carotenoids in traditional Portuguese fruits and vegetables

Carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin, were determined in 10 varieties of five fruit species (orange, pear, peach, apple and cherry) and five varieties of four species of vegetables (Portuguese coles, turnip greens, purslane, leaf beet and beetroot leaves) cultivated in Portugal and country traditional, the fruits being of protected designation of origin or of protected geographical indication. The determination was done by high performance liquid chromatography, using two metal free reverse phase columns, an organic mobile phase based on acetonitrile, methanol and dichloromethane and a UV–vis photodiode array detector. Identification was done by retention time and spectral analysis and quantification was based on peak area at 450 nm by external calibration. The analysed leafy vegetables are a very good source of lutein (0.52–7.2 mg/100 g) and β-carotene (0.46–6.4 mg/100 g) while the analysed fruits have a considerably lower content of carotenoids (lutein, 0.0032–0.16 mg/100 g and β-carotene, 0.010–0.17 mg/100 g) and a complex and variable qualitative and quantitative carotenoid composition. Most estimated relative measurement expanded uncertainties were between 0.10 and 0.31. Results indicate that the carotenoid content of the analysed items could vary with species, varieties, geographical place of production (region, site) and time of harvest, and should be addressed in the eventual production of data for food composition data bases.