No abstract

As a consequence of preventive consumer protection, the European Food Safety Authority proposed a reduction in the iodine upper level for lactating ruminants from 5 to 2 mg/kg complete feed.

Species of the genus Wolffia are traditionally used as human food in some of the Asian countries. Therefore, all 11 species of this genus, identified by molecular barcoding, were investigated for ingredients relevant to human nutrition. The total protein content varied between 20 and 30% of the freeze-dry weight, the starch content between 10 and 20%, the fat content between 1 and 5%, and the fiber content was ~25%. The essential amino acid content was higher or close to the requirements of preschool-aged children according to standards of the World Health Organization. The fat content was low, but the fraction of polyunsaturated fatty acids was above 60% of total fat and the content of n-3 polyunsaturated fatty acids was higher than that of n-6 polyunsaturated fatty acids in most species. The content of macro- and microelements (minerals) not only depended on the cultivation conditions but also on the genetic background of the species. This holds true also for the content of tocopherols, several carotenoids and phytosterols in different species and even intraspecific, clonal differences were detected in Wolffia globosa and Wolffia arrhiza. Thus, the selection of suitable clones for further applications is important. Due to the very fast growth and the highest yield in most of the nutrients, Wolffia microscopica has a high potential for practical applications in human nutrition.

The content of 5 macro elements (Na, K, Ca, Mg, and P), 6 trace elements (Fe, Mn, Zn, Cu, Se, and I), and 4 ultra-trace elements (As, Pb, Cd, and Hg) in 34 edible dried seaweed products of brown algae (Laminaria sp., Undaria pinnatifida, and Hizikia fusiforme) and red algae (Porphyra sp.) originated from China, Japan, and Korea and bought by retail in Germany was determined. The content of these elements was analyzed by spectrometric methods (ICP-AES, ICP-MS, HGAAS, and CVAAS). Assuming a daily intake with 5 g FM of algae, the contribution of the essential elements to the diet is low, with the exception of I. Brown algae contained as much as 1316 +/- 1669 mg of I/kg FM. More than 4000 mg of I/kg FM were found in several Laminaria sp. Moreover, some brown algae, such as Hizikia fusiforme, had high contents of total As (87.7 +/- 8.2 mg/kg FM).

During the last decade the iodine supply in Germany has increased significantly, but there is still a high frequency of goitre. Therefore the question of iodine bioavailability has arisen. In a two-period study 12 women were given a mixed diet of ordinary foods with milk and milk products of different batches. None of the volunteers suffered from an iodine deficiency according to WHO-criteria. Each period ended with a 9-day balance-study protocol in which all foods were provided. Food and fluid intake were registered, and urine and faeces were quantitatively collected. The iodine content was determined by ICP-MS. The mean intake in the form of solid food amounted to 175 +/- 10 micrograms I/d and to 27 +/- 15 micrograms I/d in fluid form. Milk and dairy products represented the main source of iodine (37%). Iodine was predominantly excreted in the urine (89%, 171 +/- 45 micrograms I/d) and the faeces 11% (20 +/- 11 micrograms I/d). The resulting iodine balance was approximately . In one case an iodine-rich erythrosine preparation with a low iodine bioavailability was used. Between the two periods of consuming different batches of milk and milk products no differences were observed concerning the high bioavailability of iodine.