AUTHOR=Battershill Zoe V. 

TITLE=Nutritional profiling of five New Zealand seaweeds – a preliminary assessment

JOURNAL=Frontiers in Marine Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1410005

DOI=10.3389/fmars.2024.1410005

ISSN=2296-7745

ABSTRACT=<p>This study set out to provide a preliminary assessment of nutritional profiles of five selected New Zealand macroalgae to investigate the potential of land-cultivated <italic>Ulva</italic> spp. The New Zealand seaweeds species, selected from a limited range, were either collected from the wild (<italic>Pyropia plicata</italic> from Tauranga and Kaikōura), or were sourced from commercial wild harvest suppliers (<italic>Macrocystis pyrifera</italic> and <italic>Undaria pinnatifida</italic>), and were compared to land-based cultivated <italic>Ulva</italic> species (<italic>Ulva ralfsii</italic> and <italic>Ulva stenophylloides)</italic>. Species were assessed for their content of crude protein, total lipids, carbohydrates, fibers, amino acids, mineral profiles, heavy metals and antioxidant capacity (Oxygen Radical Absorbance Capacity, ORAC). The two cultivated <italic>Ulva</italic> spp. had the highest crude protein content of the six seaweeds analyzed (approximately 21% dw, N×6.25), as expected with nutrient supplemented cultivation. They also had the highest total, essential and branched chain amino acid quantities (151, 70, and 29 mg/g for <italic>U. stenophylloides</italic> and 138, 62, and 27 mg/g for <italic>U. ralfsii</italic>). Though the two <italic>Ulva</italic> spp. were grown to the same cultivation specifications, they varied in carbohydrate and total fiber content (<italic>U. stenophylloides</italic>: 63% and 62%; <italic>U. ralfsii</italic>: 39% and 40%, respectively). <italic>Pyropia plicata</italic> collected in Kaikōura had the highest carbohydrate levels (65%) though not the highest total fiber. Both <italic>P. plicata</italic> had the highest trace minerals (417 mg/kg and 720 mg/kg for Kaikōura and Tauranga <italic>P. plicata</italic> respectively). All seaweeds analyzed showed no lipophilic antioxidants, though the two Phaeophyceae had the highest hydrophilic antioxidant content at 115 TE and 168 TE for <italic>Macrocystis pyrifera</italic> and <italic>Undaria pinnatifida</italic>, respectively. This paper provides a preliminary indication of the relative nutritional attributes of a range of potential New Zealand seaweed aquaculture targets benchmarked against sea-lettuce (<italic>Ulva</italic> spp.).</p>