Seaweed as a value-added product for the food and drink sector

Student thesis: Doctoral ThesisDoctor of Philosophy (awarded by UHI)


As a result of the increasing human population and the impacts of climate change, food insecurity continues to be a significant challenge. This is driving the need for foods (from both aquatic and terrestrial sources) which reduce both the environmental impacts of production and have enhanced nutritional and therapeutic benefits. Seaweeds are a product that could help meet these needs. Seaweeds grow naturally without the need for freshwater and fertilisers and do not compete for traditional agricultural land. The environmental impacts of harvesting wild seaweeds or growing seaweeds can also be limited. Additionally, many seaweeds contain a broad range of chemical constituents that may have therapeutic properties. To date, seaweed has not been fully exploited as a food, in part because the chemical constituents they contain, and the bioactivity of these, have not been fully characterised.
The chemical constituents and antioxidant properties of intertidal seaweeds
sampled from Caithness (North Scotland) destined for marketable food products
were determined in a range of studies. The effects of different drying treatments on a range of these chemicals and, variations in these between species, with sampling time and collection site were also determined. Results showed that seaweeds sampled around Caithness contain sufficient nutritionally important chemicals and antioxidant properties for developing functional foods and their levels are influenced by species differences, drying treatment, sampling period and site. The capacity of selected seaweed species (P. palmata and S. latissima) to accumulate selenium was explored by exposing wild-harvested seaweeds to
inorganic Se. Results showed that Se was readily accumulated in seaweed and
significant changes in lipid and protein profiles occurred as a result. Se oxidation
state, concentration, exposure duration and the seaweed species used influenced Se uptake and chemical changes. Exposing seaweed to Se could, therefore, be a potential method for developing products that help individuals meet the recommended Se intake levels and perhaps, enhance some bioactivity.
Overall, this study provides new insights into the chemical constituents and
bioactivity of seaweeds and shows that seaweed could be a product to which
significant value could be added if considered by the food and drink sector.
Date of Award18 Jan 2021
Original languageEnglish
Awarding Institution
  • University of the Highlands & Islands
SponsorsESF studentship & Scottish Funding Council
SupervisorKenny Boyd (Supervisor) & Mark Taggart (Supervisor)

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