From durum wheat to pasta: effect of technological processing on the levels of arsenic, cadmium, lead and nickel - a pilot study

A study was undertaken to investigate the effect of technological processing in pasta-making on the content of arsenic, cadmium, lead and nickel. Milling of durum wheat as well as further processing were carried out in a pilot plant. Commercial pasta samples purchased from the local market were also included for comparison. Furthermore, the effect of cooking was investigated to gain information on the actual content of the selected elements in the final ready-to-eat product. Analyte concentrations in whole grain, semolina, pasta and cooked pasta were determined by inductively coupled plasma-mass spectrometry. Milling reduced the element content in the order nickel > arsenic > cadmium > lead. In the experimental conditions of this study, slight contamination by atmospheric lead in milling/pasta-making and release of nickel during pasta-making were observed. These issues have evidently been effectively dealt with in industrial processing given that remarkably lower levels of lead and nickel were found in commercial pastas compared with the experimental samples. On the whole, commercial pasta samples showed low average levels of all the elements included in this study. Cooking caused a significant decrease of the element content in all pasta samples, with average losses of 50-60% on a dry weight basis.