Seaweed: A rich source of vitamins and bioactive compounds

Seaweed: A rich source of vitamins and bioactive compounds

Awareness of the potential health benefits of seaweed – not just for human consumption– is gathering apace, whereby selected seaweed species are now being added to aquaculture and agriculture feed with resulting benefits. One reason for this is that seaweed is a significant source of vitamins and other interesting compounds that have a number of biological functions.

Biological Functions of Vitamins

Kelp Brown

Kelp Seaweed

Vitamins can be divided into those that are either water or fatsoluble. Water-soluble vitamins include both B-complex vitamins and vitamin C. The B-complex vitamins are the largest group and have roles associated with metabolism, muscle tone, cell growth and the nervous system. For example, Nori (Porphyra sp.) and sea lettuce (Ulva sp.) are good sources of vitamin B12 which has an important role in DNA synthesis. Vitamin C is a water-soluble vitamin that is important for gum health, iron absorption and resistance to infection.

Fat-soluble vitamins include vitamin A, D, E and K. Vitamin A (retinol) plays an important role in bone growth, tooth development, reproduction and cell division. Vitamin D, another fat-soluble vitamin, is important for bone growth and maintenance. Vitamins E and K also have a number of biological functions including antioxidant activity and blood clotting. In addition to their biochemical functions and antioxidant activity, seaweed-derived vitamins have been demonstrated to have other health benefits such as reducing hypertension, preventing cardiovascular disease and reducing the risk of cancer.

Factors Affecting Vitamin Content 

Although seaweed contains both water and fat-soluble vitamins, the vitamin composition of seaweed is variable and depends on a number of factors. For example, evidence exits of seasonal variation in the vitamin content of the seaweed Eisenia arborea, where fat-soluble vitamins follow a different pattern to those that are water-soluble. Another factor affecting seaweed vitamin content is light exposure, as plants growing in bright light can contain higher levels of some vitamins.

Seaweed species is another critical factor which can affect vitamin composition. For example, the level of niacin (vitamin B3) in some brown seaweeds (e.g. Laminaria sp.) is approximately one tenth the level found in the red seaweed, Porphyra tenera. Other factors that can influence vitamin content include geographical location, salinity and sea temperature. Vitamin content can also be affected by processing as both heat and dehydration can have a significant effect on the vitamin levels.

Seaweed-Derived Compounds

In addition to vitamins, seaweed also contains bioactive compounds which have been proven to have antibiotic; antiviral; antimicrobial; mitogenic anti-inflammatory; anti-adhesion; ACE-inhibitory; antioxidant; anticancer and antithrombotic effects. These bioactive compounds include polysaccharides; proteins; amino acids; pigments phenolic compounds and sterols. The levels of these bioactive compounds also depend on factors such as species, geographical location and season.

Incorporating Seaweed into Feed

Ocean Harvest Technology’s fully sustainable feed product ‘OceanFeed™’ is a specially selected, unique blend that harnesses the bioactive compounds and vitamins present in seaweed. OceanFeed™ therefore offers a natural, fully sustainable feed ingredient formula for the aquaculture and animal feed sectors that can replace costly synthetic ingredients.

Researcher working in the OHT Lab

Researcher working in the OHT Lab

by Simon Faulkner

An image of the Facebook logo to link to the Ocean Harvest technology page

Find us on Facebook

 

Twitter Logo with a link to the Ocean Harvest Technology Twitter Page

Follow us on Twitter

 

LinkedIn logo with link to Ocean Harvest Technology LinkedIn page

Find Ocean Harvest Technology

 

 

Advertisements
Seaweed biomass cultivation likely to replace finite fossil fuels

Seaweed biomass cultivation likely to replace finite fossil fuels

Total worldwide energy consumption today is roughly 480 exajoules with almost 90% derived from the combustion of fossil fuels. Fossil fuels such as coal, oil and natural gas are limited in supply and will one day be depleted. As a result, the quest for renewable energies – being energies generated from sustainable natural resources such as sunlight, wind, tides, etc and from industrial or urban waste and biomass – began decades ago. In 2007, the 27 member states of the EU decided that 20% of its energy should come from renewable sources by 2020 (Lisbon Treaty).

Image of graph of Global biomass potential v worldwide energy consumptionThe table above shows global energy consumption and its estimated increase by 2050, and the worldwide potential of biomass for energy production based on recent studies. This clearly indicates the need for aquatic biomass to fulfil our energy consumption in a renewable and sustainable way.

At Sea Biomass Production

Since the available area for cultivation at sea is so much greater than on land (70% of the earth’s surface is ocean) and with macroalgae growth rates being much higher than of conventional land crops, the potential for biomass production at sea is enormous. In addition, aquaculture for energy production can avoid the often heated debate surrounding food crops for fuel (food-energy nexus); sustainability; water usage; pesticides and land use change. Equally, fertilisation, which has a major affect on greenhouse gas balances of crops on land, can be altered or even diminished when cultivating in an aquatic environment.

Greenhouse gas emission worldwide using aquatic biomass for energy and fuel is, in most cases, much less, compared to the more conventional biofuels, produced from land-based crops. Seaweed cultivation is a traditional practice in East Asia. A total of 15 million tonnes wet-weight is cultivated per annum, making it the biggest aquaculture venture on the planet. Of all seaweed harvested, 93% is produced from aquaculture.

Seaweed cultivation in Europe is still in a developmental phase with only a few commercial farms in operation, notably in France, Germany and Ireland, where the focus is on small-scale production for high added-value seaweeds. Total combined production of these farms is less than 100 tonnes wet-weight per annum.

Image of Declan Hanniffy checking some seeded ropes on the farm

Declan Hanniffy checking some seeded ropes on the farm

Multi-purpose Usage 

Seaweed is a source of food; food additives and high added-value speciality products such as pharmaceuticals and cosmetics. It also has huge potential as a biomass source. Therefore, the combination of bio-refinery, with the isolation of valuable seaweed components for high-value products and renewable energy production, will be necessary in future years.

Today, aquatic biomass cultivation is a logistically complex multi-step process onshore and offshore, and is mainly based on small volume production on long ropes and manual harvesting. As a result, production costs per biomass unit are much too high. Urgent research is therefore needed to develop near shore and offshore cultivation in the western world, to produce a sustainable, consistent and cheap feedstock with a high carbohydrate level.

No matter the species, it usually takes significant time to develop into a booming aquaculture industry. With oysters for example, it took almost 30 years. Seaweed too is likely to go through a similarly lengthy developmental process, despite significant breakthroughs such as the biochemical process to convert algal carbohydrate into ethanol. Indeed, several initiatives have already been funded, amongst them the MERMAID and Energetic algae (ENALGAE) projects in Denmark – the latter with Irish participation lead by Dr Maeve Edwards of NUI, Galway.

Seaweed as Feedstock

Another EU project with Irish involvement that is looking at seaweed as feedstock for biofuel production is the € 3.5 million EU funded project, AT~SEA which commenced this month. The project involves partners from The Netherlands, Portugal, Belgium, France, Norway, UK and Oceanfuel Ltd from Ireland.

The project will explore high-volume cultivation on large textile substrates, with the aim of reducing production costs, thus making offshore production of biomass a high-potential source for renewable energy. It is generally accepted that Europe’s industries must become more efficient, more environmentally sustainable and more competitive.

With the AT~SEA project we want to implement and realise this objective via a tangible case. Expertise from four sectors: textile; offshore; renewable energy and biotechnology, will be combined to generate new knowledge (textile for offshore use; textile-seaweed interaction), which will be used to develop an innovative technological solution (textilebased offshore production of aquatic biomass) to respond to one of the grand challenges (sustainable and renewable energy supply).

Image of Laminaria hyperborean growing in the intertidal in Ireland

Laminaria hyperborean growing in the intertidal in Ireland

This project will focus mainly on cultivating the native brown seaweed Laminariaceae in North Western European Atlantic waters. These brown algae are known to grow rapidly and produce a high biomass, and to have high carbohydrate content suitable for fermentation into ethanol or furans and could be a sustainable alternative to biofuels and plastics.

Twitter Logo with a link to the Ocean Harvest Technology Twitter Page

Follow us on Twitter

An image of the Facebook logo to link to the Ocean Harvest technology page

Find us on Facebook

Seaweed- Ireland and Abroad

Seaweeds have been used in Ireland for decades for a variety of purposes; however the seaweed industry is still the Cinderella of the aquaculture and seafood Industry. Why is that?

Image of Laminaria hyperborean growing in the intertidal in Ireland

Laminaria hyperborean growing in the intertidal in Ireland

There are diverse market application for seaweeds ranging from food, functional foods and health supplements to agricultural applications, cosmetics, biotechnology and aquaculture. Besides we have over 600 different species of seaweed identified from Irish waters.

Unfortunately seaweeds have never been taken seriously in Ireland compared to fish, mussels, scallops and Oyster and ample funding has gone into developing this resource. The recession of late has made things worse with BIM completely abandoning its seaweed program. Again it is the lack of vision or no vision at all! Countries such as Norway are setting up large scale programmes to develop their seaweed resources and seaweed aquaculture for integrated multi-trophic aquaculture. This is to improve the environmental record of fish farming and progress biofuel development while Norway is a country that has large oil resources.

If we look at seaweed at a global scale it is a different story. Worldwide seaweed aquaculture is a growing sector. Latest figures show a production of over 15 million tonnes wet weight with an economic value of US$ 6.5 billion. The majority of seaweed produced by aquaculture is used for human consumption and for extraction of hydrocolloids although the application for biofuels and other valuable ingredients is starting to play an important role. Moreover, new applications of algae and specific algal compounds in different sectors, such as functional foods, cosmetics, biomedicine and biotechnology are developed. Recent trends in life style towards natural, healthy products are favourable for advancement of seaweed consumption, applications and aquaculture.

Image of Ocean Harvest Technology Products

Ocean Harvest Technology Produce

Luckily the private sector in Ireland including Ocean Harvest Technology is rapidly developing the seaweed resources initiating new ideas and implementing their own R&D programs. It is through these initiatives that the future outlook looks good for our forgotten green gold on our shores. Especially the emerging markets such as functional foods and biofuel development from seaweeds will further enhance the sector. Bioethanol is currently produced from land-based crops such as corn and sugar cane, and the continued use of these crops will drive the food versus fuel debate more as demand for ethanol increases. Aquaculture of seaweeds is sustainable, use less or no agricultural inputs (pesticides, fertiliser, land, water), and not be part of the human or animal food chain. Cultivated seaweeds could be used as an alternative biomass source for bioethanol production and production of other high value added chemicals. Seaweed biomass represents an abundant and carbon neutral renewable resource with potential to reduce green-house gas emissions and the man-made impact on climate change. Coupled to fish farming it could even help alleviate environmental issues and recycle nitrates and phosphates.

The recently proposed deep water fish farm at the back of the Aran Islands producing 15,000 tonnes on top of the 13,000 currently produced nationally should incorporate aquaculture of seaweeds. This would allow for improving the environmental record, sustainability and carbon credits of the operation and could form part of the fish feed used for the fish creating the ultimate recycling of nutrients. Now that would be a long term vision!

Twitter Logo with a link to the Ocean Harvest Technology Twitter Page

Follow us on Twitter

An image of the Facebook logo to link to the Ocean Harvest technology page

Find us on Facebook