Elemental content and nutritional study of blood orange juice

BACKGROUND: The elemental content of Sicilian red orange juices and the bioaccessibility of many elements of particular nutritional interest was evaluated. RESULTS: The elemental content of fresh juices from Sicilian blood oranges was analysed by ICP-OES, GF AAS, HG-AAS and CV AAS. Among the macroelements (Na, Ca, K, Mg and P), potassium occurred in the greatest amount, with 3.64% of the requested RDA for 100 mL of juice daily intake. The values of RDA 100 mL(-1) of juice for Mg, P, Ca and Na resulted 1.61%,1.26%,0.59% and 0.09% respectively. For the trace elements Cr, Cu and Se, the RDA 100 mL(-1) of juice were 9.20%, 7.14% and 1.82%, respectively. In vitro tests simulating the digestive process showed high bioaccessibility only for boron and manganese while that of copper, zinc and iron were consistently lower. CONCLUSIONS: Sicilian blood orange juices gave different results from non-pigmented orange juices interms of a higher content of copper, boron and lower content of chromium and manganese. However, among the nutritionally important elements, only manganese showed high bioaccessibility. The low bioaccessibility found for iron, zinc and copper is likely due to the presence in the orange juice of ligands such as polyphenols and organic acids. (C) 2009 Society of Chemical Industry