US EPA

1353547 

Journal Article 

Nutrient and heavy metal content of edible seaweeds in New Zealand 

Smith, JL; Summers, G; Wong, R 

2010 

1 

New Zealand Journal of Crop and Horticultural Science
ISSN: 0114-0671 

38 

1 

19-28 

10.1080/01140671003619290 

WOS:000279918800003 

The nutritional composition of four commercially available
seaweeds, Macrocystis pyrifera, Undaria pinnatifida, Porphyra and Ecklonia radiata, was compared
with six wild-harvested species, Ulva stenophylla, Porphyra, Ecklonia radiata, Durvillaea
antarctica, Hormosira banksii and Undaria pinnatifida. In the wild-collected species, ash
contents were high (19.8-26.6% dry weight). Carbohydrate content ranged from 45.4-66.9%, while
protein varied from 6.1-32.7%. Some species had high levels of potassium (<71.2 g/kg) and calcium
(<15.3 g/kg). Total arsenic concentrations were high in some species (<97 mg/kg), but the
dominant forms were the organic arsenic compounds that are regarded as non-toxic. Inorganic
arsenic was well below the New Zealand regulatory limit. The variation in proximate composition
and mineral content was high among species collected at different times or locations and between
different species. New Zealand's native and naturalized seaweeds are comparable to other edible
seaweeds and would be a healthy addition to normal diets. 

seaweed; proximate composition; minerals; arsenic