Copper in foods, beverages and waters from South East Spain: influencing factors and daily dietary intake by the Andalusian population

Abstract

The copper content of 225 food, 49 beverage and twelve potable water samples were determined using atomic absorption spectrometry (AAS). Analyses of NIST and BCR reference materials demonstrated the accuracy of this technique. The highest copper levels were found in dried fruit and legumes, followed by organ meats, molluscs and crustaceans, cephalopods, cereals and sausages, respectively. In cereals, legumes and fruit, copper levels increased significantly with increasing levels of protein and decreasing carbohydrate content (p < 0.001). In meat and meat by-products, copper concentrations found in organ meats were significantly higher (p < 0.01). In fresh fish products, copper levels in shellfish were significantly higher than those measured in fish (p < 0.001). In vegetables, the copper concentrations found in mushrooms were significantly higher (p < 0.005). Mean copper concentrations analysed in cheese were statistically higher than those determined in other dairy products (p < 0.01). In beverages, copper levels determined in rum and juices were significantly higher (p < 0.001). Beverages for which a vegetable component was directly used in their manufacturing process (juices, wines and beers) had statistically higher copper levels when compared with fresh drinks. The daily dietary intake (DDI) of copper in the Andalusian diet was 1979 μg day⁻¹ per person. Cereals, meat, meat by-products and vegetables are the food categories that are the main source of copper in the daily diet. Taking into account the dietary reference intakes and upper levels (900 and 10, 000 μg Cu day⁻¹ for healthy adults, respectively), the mean copper DDI found indicate that for most of healthy adult individuals from the area, no adverse effects occur in relation to copper nutrition (deficiency or toxicity). Potable waters supplied 53 μg day⁻¹, which constitutes on average 0.025% of the maximum tolerable daily intake of this element set by the Joint FAO/WHO Expert Committee.

Keywords:

• copper
• foods
• food processing
• macronutrient influence
• daily dietary intake
• atomic absorption spectrometry (AAS)