Iron Content, Iron Speciation and Phycocyanin in Commercial Samples of Arthrospira spp.

Cyanobacteria are characterized by high iron content. In this research, we collected ten commercial samples of Arthrospira spp. sold as food supplement to determine iron content and assess whether iron speciation showed variability among samples and changed respect to A. platensis grown in controlled conditions. Particular attention was also paid to phycocyanin, as an iron-binding protein. In six of the ten samples, 14 essential and non-essential trace elements were analysed using ICP-MS. Iron content measured in samples using atomic absorption spectrometry (AAS) varied from 353 (sample S5) to 1459 (sample S7) µg g-1 dry weight and was in the range of those reported by other authors in commercial supplements. Iron speciation was studied using size exclusion chromatography followed by the analysis of the collected fraction for the determination of iron by AAS and for protein separation using SDS-PAGE. Overlapping chromatographic profiles were obtained for total proteins, phycocyanin and iron, although quantitative differences were evidenced among the samples analysed. In most samples, iron was mainly bound to ligands with high molecular mass; however, in four samples iron was also bound to ligands with low molecular mass. In fractions containing the most relevant iron burden, the principal protein was phycocyanin, confirming its role as an iron-binding protein in commercial samples.

Trace Elements in Home-Processed Food Obtained from Unconventional Animals.

Wild animals have been used as food since ancient times and, currently, the consumption of unconventional animals is increasing worldwide. The process of cooking meat using traditional recipes includes a variety of ingredients, which can influence the total metal intake from the diet. In this study, the concentrations of eight essential (Fe, Zn, Cu, Mn, Se, Ni, Mo, and Co) and six non-essential (Pb, Cd, Hg, Al, As, and Cr) trace elements were determined in home-processed food obtained from snails and from three common species of game animals (woodcock, pheasant, and hare), seasoned with anchovies, mushrooms, and different vegetables using inductively coupled plasma mass spectrometry (ICP-MS). In general, Fe was the most abundant trace element, ranging from 18 ± 8 µg/g in pheasant to 99 ± 76 µg/g in snail, and Co was the least abundant, ranging from 0.007 ± 0.003 µg/g in hare to 0.093 ± 0.048 µg/g in snail. Regarding the non-essential trace elements, Pb concentrations showed wide variations, reaching a concentration of 17.30 µg/g in hare, while Cd concentrations were higher in snail, ranging from 0.18 to 0.46 µg/g. These alternative food sources can offer an important contribution to the human nutritional requirements of essential trace elements, in particular of Fe. The high concentrations of Pb and Cd present in some samples should be considered as potentially dangerous for the consumers.