Plants & People

Seaweeds, the “food factories” from the sea

Unlocking the secrets of seaweed could have major benefits for human health.

Seaweeds are efficient “factories” of multiple compounds including carbohydrates, proteins, lipids and phenolics that are able to improve human health when used as food by reducing your blood pressure or the risk of suffering cancer and cardiovascular diseases.

Seaweeds have enjoyed a long tradition of use as food in Asian countries, being used in soups (miso) or sushi, adding the particular flavour appreciated in these dishes (“umami” flavour). The recent discovery of the health benefits of seaweed ingredients has increased the interest of extracting these compounds and using them rather than using all the macroalgae. For example, seaweeds are currently used as a source of hydrocolloids or carbohydrates with thickening and gelling properties that can be used as fat replacers in multiple food formulations or added into foods due to their health benefits. Thus, there is an interest in using seaweeds as a factory of carbohydrates, but also other compounds that are currently being discarded.

The use of seaweeds as potential factories of healthy compounds present multiple scientific challenges including the need to understand the variable composition of seaweeds and to research new ways to produce seaweed compounds in an efficient manner.

Diagram showing input from Seaweed Cariability, through the Extraction Technologies, to the output of Food Ingredients.

Understanding the variable composition of seaweed

Multiple studies described seaweeds as rich in carbohydrates (up to 60%), with medium amounts of proteins (10-47%), low in lipids (1-3%), and variable contents of minerals (7-38%). Seaweeds produce variable production amounts of compounds depending on their class (i.e. green, red or brown seaweed), species and environmental factors affecting macroalgae. For example, variations in temperature or solar radiation every season may induce stress in macroalgae due to the formation of reactive oxygen species that will damage the cells. As a defence mechanism, seaweeds will produce a high amount of antioxidants to protect themselves during these periods. Foods enriched with antioxidants can help in the prevention of diseases and thus, multiple companies are currently interested in incorporating antioxidants in their formulations.

Understanding seaweeds is challenging, as multiple factors can affect their composition. A deeper understanding of seaweeds’ biology will help to establish cultivation or optimum harvesting times and cultivation techniques to obtain high amounts of health beneficial compounds.

Production of seaweed compounds

The production of seaweed compounds requires processing macroalgae to break down the cell walls and release the compounds from seaweeds. The industrial extraction of seaweed compounds is currently based on traditional or conventional methods that are time consuming and use large volumes of toxic organic solvents to break-down the cells.

Recently, new technologies including the application of ultrasounds, microwaves or combination of both forces are being explored to extract multiple health beneficial compounds from macroalgae. The application of novel extraction technologies has remarkable advantages compared to conventional techniques, reducing the extraction times and temperatures and thus, contributing to lower the energy consumption and environmental impacts of the extraction methods. However, most of these applications are currently limited to small-medium scale, and thus, there is a need to investigate further the use of these technologies to obtain multiple seaweed compounds and optimise these technologies at pilot and industrial scale.

Despite these multiple challenges due to the high variability of the composition of seaweeds, macroalgae can be considered as an excellent factory of health beneficial compounds that will require the collaboration of scientists from multiple disciplines in order to understand the biology of seaweeds, the most efficient processes to break-down seaweed into their multiple compounds and the use of seaweed ingredients to produce healthier food products that could help in the fight against chronic diseases such as cancer, cardiovascular diseases and diabetes.

About the author

Marco Garcia-Vaquero is an Assistant Professor of the School of Agriculture and Food Science at University College Dublin (Ireland).His research interests include the extraction, purification and characterization of natural compounds from seaweed, microalgae and other agricultural by-products with potential applications in food, animal feed, pharmaceutic and cosmetic industries.

Email: marco.garciavaquero@ucd.ie

Website: https://people.ucd.ie/marco.garciavaquero

Want to contribute to this research?

University College Dublin, School of Agriculture and Food Science has a PhD in Food Science open. There’s a scholarship open to both European and non-European students for four years starting in January 2021. The studentship award includes full tuition fee waiver and a PhD stipend of €18,000 per annum.

You can find out more at Euraxess.

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