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Seaweeds are rich in essential dietary minerals, often lacking in terrestrial plant foods, with interest in Australian seaweeds rapidly increasing. We screened six Australian brown seaweeds with commercial potential for dietary mineral composition: Cystophora torulosa, Caulocystis uvifera, Durvillaea potatorum, Ecklonia radiata, Hormosira banksii and Phyllospora comosa. Spatial replicates of each species were collected from three non-urbanised sites remote from pollution sources and processed for human consumption. Dried samples were analysed by inductively coupled plasma mass spectrometry (ICP-MS) for 12 essential dietary minerals. Overall dietary mineral composition differed significantly amongst all species, except between sargassaceous species C. torulosa and C. uvifera; but concentrations of individual elements varied in complex ways. All species investigated had high concentrations of dietary minerals essential for optimal human health if consumed in realistic quantities (e.g. 10 g day−1 DW) as part of balanced diets, including the most common dietary minerals deficient in humans (iodine, iron, zinc, magnesium, calcium and selenium): iodine (888 ± 100 mg kg−1 DW) and zinc were highest in P. comosa; iron and calcium were highest in C. torulosa, but calcium was also high in E. radiata, H. banksii and D. potatorum; magnesium was highest in H. banksii, D. potatorum and P. comosa; selenium concentrations exceeded those previously reported for seaweeds for all species, except D. potatorum. The best nutritional outcomes may be achieved by regularly consumption of a diversity of seaweed species. However, further investigation into ways to reduce iodine content in some species may be required to maximise health benefits from regular consumption of these Australian seaweeds. [ABSTRACT FROM AUTHOR]

This study aimed to determine the nutritional composition, perceived quality and palatability of nine Australian seaweeds (wild-harvested species not yet exploited for human consumption; Laurencia filiformis, Codium galeatum, Cystophora polycystidea, Cystophora torulosa, Phyllotricha decipiens, Durvillaea potatorum, Hormosira banksii, Phyllospora comosa, Ecklonia radiata), and compare them to four of the commonest commercially available species (Pyropia tenera, Sargassum fusiforme, Saccharina angustata, Undaria pinnatifida). Nutritional value varied amongst species and inconsistently with time. Four Australian species had higher total lipids than all commercial products in this study and amongst the highest values reported in the literature for seaweeds. Moreover, nine out of 13 species had an omega-6 and omega-3 fatty acid ratio favourable for human health (≤ ~ 1). Eicosapentaenoic acid (EPA) was present in higher concentrations than docosahexaenoic acid (DHA) in all species. Highest DHA concentrations were found in Australian species, whilst EPA was very much higher in Pyropia tenera (nori) than all other species. Crude-fibre and protein contents were high for most Australian and commercially available species on a dry weight basis. A subset of Australian and commercially available seaweeds was prepared and cooked as soup or salad for sensorial (organoleptic) evaluation. There were no significant differences in consumer acceptance of any seaweeds when prepared in the soup, but acceptance of the salad dishes differed significantly, influenced primarily by a preferred texture of commercial hijiki (S. fusiforme) over the Australian species. This study identifies specific Australian seaweeds that may be viable as commercial foods. Regular consumption of 10 g (dwt) of a mixture of the seaweeds tested in this study may improve human health by contributing health-promoting fatty acids, fibre and protein to an omnivorous diet, with higher levels of consumption required for vegetarians and vegans to meet daily requirements of favourable fatty acids and protein from non-animal sources. However, further research must also examine potentially toxic effects of regularly consuming seaweeds in these quantities. [ABSTRACT FROM AUTHOR]