We try not to take ourselves too seriously here at Ocean Harvest so we decided to have some fun with some of the Kelp which we had drying on our floor today. Have a look at the photos and tell us what you make of our heart! Happy Valentines Day everyone.
Seaweed is a natural and sustainable ingredient with a lot of different functional biological properties, amongst them protein. Protein are biochemical compounds comprising one or more polypeptides typically folded into a globular or fibrous form that facilitate biological functions in the body.
Although the structure and biological properties of seaweed proteins are still poorly documented, the amino acid compositions of several species have been known for a long time. Habitat – and especially seasonal variation – has an effect on proteins, peptides and amino acids in seaweed. The protein fraction of seaweed varies with the species but is generally low in brown seaweed, <15%. Higher protein contents are recorded for green and red seaweed, up to 40%. These levels are comparable to those found in highprotein vegetables such as soybeans.
Essential Amino Acids
Most seaweed species contain all the essential amino acids and are a rich source of the acidic amino acids, aspartic acid and glutamic acid and in general are higher than those found in terrestrial plants.
One bioactive protein present in algae are lectins, which are a structurally diverse group of carbohydrate binding proteins. Marine algal lectins exhibit antibiotic, mitogenic, cytotoxic, anti-nociceptive, anti-inflammatory, antiadhesion and anti-HIV bioactive properties and are currently commercially produced for a variety of purposes.
Peptides are 2-20 amino acid long chains which once a protein is broken down are released and become bioactive and fulfil certain functions in the body. The depsi-peptide kahalalide-F from Bryopsis sp. – a green alga is active in the treatment of lung cancer, tumours and AIDS. Many other bioactive functions have been ascribed to algal peptides. When protein and peptides are broken down to their individual building blocks we have amino acids. The eight essential amino acids (cystine, isoleucine, leucine, lysine, methionine, phenylalanine, tyrosine and valine) cannot be synthesised by animals, nor can they be replaced by other ‘less valuable building blocks.
All essential amino acids are present in brown and red seaweed species; red species feature uniquely high concentrations of taurine – an ingredient found in a well-known energy drink.
Ocean Harvest Technology in association with several universities has already embarked on optimising extracting total protein – finding and isolating bioactive peptides for applications in aquaculture and animal feed.
Why is this important?
Because a global protein crisis is looming. Currently, about 5 million tonnes of fishmeal is produced and used as feed ingredient in livestock and aquaculture. Virtually all fishmeal is used as a high protein ingredient in feed for farmed land animals and farmed fish. The typical inclusion rate for fishmeal in farm animal diets is 1-5% of dry matter, mainly in specialist diets – e.g. for weaner pigs. A typical farmed salmon diet contains 20-30% fishmeal.
In the ten years to 2002, aquaculture expanded worldwide by more than 9% per annum and since then at a slightly slower rate. While the use of fishmeal will consequently increase – improved efficiency and some substitution means this is likely to be at a slower rate.
Nevertheless, fish stocks used for fishmeal are diminishing and prices are rising. A lot of work has taken place on plant protein as replacement; however, often these plant proteins like soya are less suitable for use in aquaculture due to anti-nutritional factors or lower performance. The large fish-feed manufacturers currently purchase more than €1bn in fish protein and oil per year, sourced primarily from South America by harvesting wild fish from around the world.
Two of the biggest financial and environmental costs for these companies and all fish-feed processors are increasing shortage and the spiralling cost of fish protein. It takes 3-4 kg of wild fish (herring, capelin for example) to create 1kg of fish meal. This is a completely unsustainable scenario that has a major negative impact on the ocean environment.
Seaweed protein extracted for example by Ocean Harvest Technology has a high purity, comprising over 80% protein in contrast to fishmeal at about 65%. It is also extremely popular amongst aquaculture feed manufacturers because of its excellent amino acid profile.
When large-scale production of seaweeds starts in earnest (e.g. in Ireland), it most definitely could help alleviate the problem currently experienced with fish meal and plant protein replacements. Moreover, seaweed protein is derived from a sustainable marine resource and does not have the stigma of being a food crop.
These attributes make seaweed protein an excellent source for use in aquaculture feeds and show great potential for it in the future.
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?
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.
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!
Certain seaweeds have a relatively high level of the amino acid L-Glutamate, specifically Laminaria species which are brown seaweeds popularly called kelp or certain red seaweeds like Porphyra commonly called Nori, sloke or laver and which are used as wrapper for sushi. Apparently, our taste buds on the tongue and other regions of the mouth have receptors for this specific amino acid and can detect this amino acid as a specific taste described as meaty or brothy with a long lasting, mouth-watering and coating sensation over the tongue. They refer to this savoury taste as Umami. Umami has a mild but lasting after-taste difficult to describe. It induces salivation and a furriness sensation on the tongue, stimulating the throat, the roof and the back of the mouth. Umami is one of the five recognized basic tastes together with sweet, sour, bitter, and salty. Umami is a Japanese word invented by Professor Kikunae Ikeda of the Tokyo Imperial University in 1908 which means pleasant savoury taste and was made up of two words umai meaning “delicious” and mi meaning “taste”. He found that glutamate was responsible for the Umami taste of the broth from kombu seaweed.
It took a long time before umami was recognized as a basic taste; but in 1985 at the first Umami International Symposium in Hawaii, the term Umami was officially recognized as the scientific term to describe the taste of glutamates and nucleotides. Now it is widely accepted as the fifth basic taste. Umami represents the taste of the amino acid L-glutamate and 5’-ribonucleotides such as guanosine monophosphate (GMP) and inosine monophosphate (IMP). Umami has the ability to balance taste and round the total flavour of a dish.
Using glutamate is not new and has a long history in cooking. The best example is the fermented fish sauces (garum), rich in glutamate, in ancient Greek and Roman times. The sauce was generally made through the crushing and fermentation in brine of the innards of various fishes such as mackerel, tuna, eel, and others.
A student of professor Ikeda, Shintaro Kodama, discovered in 1913 that dried bonito flakes (a small kind of Tuna) contained another umami substance. This was the ribonucleotide IMP. In 1957, Akira Kuninaka realized that the ribonucleotide GMP present in shiitake mushrooms also conferred the umami taste. His most important discovery was the synergistic effect between ribonucleotides and glutamate. When foods rich in glutamate are combined with ingredients that have ribonucleotides, the resulting taste intensity is higher than the sum of both ingredients. This synergy of umami provides an explanation for various classical food pairings, starting with why Japanese make dashi with kombu seaweed and dried bonito flakes.
The optimum umami taste depends also on the amount of salt present in the dish. Low-salt foods can maintain a satisfactory taste with the appropriate amount of umami. In fact, low salt soups tasted better when the soup contained umami, whereas low-salt soups without umami were less pleasant. In addition to enhance the deliciousness, umami compounds can to some extent substitute sodium chloride in foods. Thus by integrating seaweed into industrial produced foods and meals, human consumption of salt (sodium chloride) can potentially be decreased with the associated health benefits of doing so.
Why reduce salt intake? Apparently salt intake has become quite a problem in Europe, with Europeans consuming roughly twice the recommended limit of salt each day, causing widespread high blood pressure and placing millions at risk of heart attack and stroke. These conditions cause many deaths and cost billions in healthcare expenses. Only ca. 10% of the sodium in our diets comes from saltshakers, while over 80% is added to foods before they are sold.
Over the last couple of years there was a voluntarily reduction of salt by the food industry in Europe with some successes e.g., in the U.K., where they have already reduced salt in packaged and restaurant foods and managed to implement salt reductions of 40% or more in some food products. If we look at Ireland, salt levels remain high in processed foods as the economic climate means many businesses no longer see reducing levels as a priority. The Food Safety Authority of Ireland (FSAI) is disappointed the food industry has lost interest in its voluntary salt reduction programme. Especially in view of that Irish people are still consuming far too much salt.
The recommended daily limit for sodium intake is 2,3 gram for most adults, while we consume closer to 5-6 gram a day. Some food products, such as deli-meat sandwiches, pack more than the recommended daily intake of sodium in one serving. But much of the salt in diets comes from breads, muffins and other foods that don’t taste salty.
Developments in food technology, including alternatives to salt and other sodium-based ingredients, manufacturing and distribution chain processes, and acceptable food safety testing, will all be necessary to ensure further progress, as will rebalancing product flavours to maintain consumer acceptability. This is where the Umami taste from seaweeds could play a major role.
Seaweed is an underutilized food in the Western diet, while it has an important role in Eastern food cultures. Its content of umami compounds and a beneficial nutritional composition have great potential to become part of a healthy, tasty and sustainable diet, while able to replace salt in many processed food products. Marketing of seaweeds and implementation of these in our food culture will not only contribute to a healthy and well tasting diet based on local ingredients, but also support a sustainable food production and increase business opportunities for local seaweed farmers and food industries. Creating foods and meals with seaweeds that appeal to the consumers require gastronomic innovation at all levels of the food sector, from high-end restaurants to the food industry. The success of seaweed as a new food resource also requires an increased awareness of the consumers on the qualities of consuming seaweeds and how to use seaweed products in cooking. Ocean Harvest Technology Ltd has developed several salt replacement and taste enhancing mixtures that can be taken on board by food product developers and the food industry and create a whole new market for novel food products while reducing salt levels in the diet.
Anecdotal observations over many years have suggested that seaweeds are an important nutritional resource for terrestrial and aquatic species. Sheep are known to graze regularly on seaweed if they have coastal access. Cod have been observed grazing on seaweed immediately before breeding, while single species of seaweed have demonstrated a significant improvement in disease resistance when included in diets for farmed shrimp. Over the last 10 years the fed aquaculture industry has been bombarded by concerns over environmental impact, animal welfare, sustainability and food safety concerns.
Seaweeds have been used historically as a feed supplement, but only as single species of seaweed. Benefits from use of seaweed as feed supplements are well documented in many research publications. Different species of seaweed contain many different bioactive molecules. These bioactive ingredients are:
- Lectins, phycobiliproteins, peptides and functional amino acids such as laminine and hydroxyproline
- Fucoidan, laminarin, alginic acid, mannitol, carageenan, agars and other short chain oligosaccharides
- Antioxidants, phenolic compounds and pigments
- Fatty Acids
Scientific evidence of the last decade has shown that these ingredients have antibiotic, antiviral, antimicrobial, mitogenic, anti-inflammatory, anti-adhesion, ACE-inhibitory, antioxidant, anti-cancer and antithrombotic effects with immune-modulation and cytomodulatory effects.
In addition to these ‘bioactive’ molecules seaweeds are a rich source of vitamins and minerals and the right blend of seaweeds can replace most or all of the ‘synthetic’ sources of these ingredients that are used in aquatic and animal feeds.
With this in mind Ocean Harvest Technology Ltd, an Irish company operating out of Milltown, saw an opportunity and formulated and tested a seaweed-based ingredient, OceanfeedTM that addresses the issues of sustainability and the use of ‘chemical’ ingredients that gives significantly improved performance in growth rate, feed conversion ratio, mortalities, disease and lice resistance and finally flavour and texture of Salmon and shrimp. Many of these synthetic additives such as colorants, antibiotics and preservatives end up in the farmed salmon and have led to recent health scares. An urgent need has arisen for cost-effective alternative and sustainable organic and natural fish feed ingredients and Oceanfeed™ can be part of the solution.
Exhaustive trials were run at the Trial Feed Unit owned and operated by Marine Harvest on the Scottish west coast. The feeds, both reference and test, were manufactured by EWOS (UK) Ltd. The fish were mixed sex Atlantic Salmon smolts with a starting weight of 145 gms and fish were fed to satiation, light regime followed natural photoperiod and water temperature was ambient. All trials were run in triplicate and the cages were inspected daily. All other physical parameters were measured on a daily basis, and mortalities were recorded on a daily basis. Fish were sampled and assessed against standard farming KPI’s (Key Performance Indicators). Evaluation included growth rate, feed conversion ratio (FCR), condition factor, yield, fat analysis, lice counts, pigmentation, lipid content and profile, flesh flavour and flesh texture. Samples of whole guts were taken for microbiological evaluation and samples of lower intestine were taken (being immediately fixed in buffered formalin) for histological examination. Scottish Quality Cuts (SQC’s) of flesh were taken for lipid analysis, lipid profile, protein analysis and pigment analysis.
The trial was run for over 1.5 years to go through to complete life cycle from smolt up to 5-7 kg salmon. The following benefits were shown at a 15% inclusion levels of oceanfeed compared with a high grade reference diet:
- Higher weight gain
- FCR lowered by 0.1 point
- Uptake of pigmentation from algae up to 23-24 on SalmoFan.
- Higher Omega 3 oil levels in feed
- Overall health improvement and faster recovery from Anesthetic
- Significant lower sea lice on fish, up to 60% less gravid females and adult stages of male and female lice
- 55% lower mortality rates
- No deformities or runts
- Improved gut health as shown in histological staining of gut sections of trial fish. Caused by short chain Oligosaccharides
- Significantly improved taste and texture of fish
- Low fat (belly flaps) and leaner fish
- Easier to process, fillet and smoke (no oil leakage)
- Improved environmental record due to no release of foreign synthetic matters in the feed. Seaweed is a marine product harvested from the marine environment in a sustainable way.
The shrimp industry is a factor 10+ larger compared to salmon, with salmon needing about 1.8 million tonnes of feed per annum and shrimp 28 million tonnes of feed. With the results from the salmon trial we could with some adjustments do a similar thing and replace premixes in shrimp feed and improve disease resistance. This shrimp seaweed ingredient called Oceanfeed™- shrimp contains a plethora of natural bioactive compounds which by incorporating in the diet can modulate several functions in shrimp and assist in the control of chronic diseases and viral infections found in farmed shrimp. It allows for disease free farmed shrimp to be reared in a more natural and sustainable way, easing concerns on environmental impact and sustainability. Late last year and early this year several shrimp trials were undertaken using a 10% Oceanfeed diet compared to high standard reference shrimp feed in P. monodon and vannemei, globally the two most cultured shrimp. At the end of the trial part of the shrimps were blast frozen and send for taste testing. After the growth trials OHT commissioned the Shrimp Research unit of the University of Ghent to conduct challenge tests to test for the effect of the inclusion of Oceanfeed on viral and bacterial diseases. The results showed a positive outcome of having Oceanfeed incorporated at 10% in the diet. In brief the following results were obtained:
- Higher weight gain (Shrimp fed with Oceanfeed at harvest were 5.2% heavier on average than control)
- FCR lowered by 0.1 point
- Uptake of pigmentation from algae in Shrimp.
- 25% lower mortality rates
- No deformities or runts
- Significantly improved taste and texture of the shrimp. Tested and proven with independent taste panels
- Improved survival and onset of mortality times
- Improved environmental record due to no release of foreign synthetic matters in the feed. Seaweed is a marine product harvested from the marine environment in a sustainable way.
As most seaweeds that we use for Oceanfeed™ are still from sustainable wild harvest we looked at the possibility of cultivating specific seaweeds of high importance for our feed formulations. Of course seaweed cultivation is nothing new and has been practised for over 300 years in Japan. In Asia, seaweed cultivation is by far more important in terms of output and value than any other form of aquaculture. Looking at a global scale the value of cultivated, managed and wild harvested seaweeds exceed over € 7.0 billion with 89% of this value derived from aquaculture. Seaweeds are also the industrial sources of carrageenans (Chondrus, Eucheuma and Kappaphycus), alginates (Ascophyllum, Laminaria, and Macrocystis) and agars (Gelidium and Gracilaria). These important polysaccharides are used in the food, textile, paint, biotechnological and biomedical industries and have a global value of approximately € 600 million. Seaweeds have significant value in agriculture as soil additives, fertilizers and seaweed meals with their value over € 20 million. The increasing demand for safe, healthy, and minimally processed foods is creating an opportunity for seaweed products as functional foods, nutraceuticals, and alternative medicinal products. In Ireland, over the last 5 years a strong interest has developed in seaweeds as functional food or nutraceuticals. Research is focused on the establishment of low-volume high-value seaweeds in aquaculture. Moreover, new applications of algae and specific algal compounds in different sectors, such as food supplements, cosmetics, biomedicine and biotechnology are developed. Recent trends in life style towards natural, healthy products are favourable for advancement of seaweed aquaculture in Ireland
Additional environmental benefits
Seaweeds are well-able to reduce N and P in their surrounding environment. If no fertilizers are used seaweed farms could act as N and P filtering units in near coastal environments reducing eutrophication risks from agricultural land run-off .Moreover, seaweed farms can act as short-term CO2 sink reducing acidification of global oceans. Inputs of biodegradable organic matter and inputs deriving from fertiliser run-off together with run off or dilution from finfish and shellfish rearing in near-shore waters and land based activities have many effects on the quality of coastal inshore waters and are a primary cause of eutrophication due to increased availability of nutrients. Kelp farms (inshore and nearshore) are able to act as bio-filters and are able to remove nitrates and phosphates from the surrounding eutrophic inshore waters. This allows for increased production of farmed seaweed as demonstrated by Chopin et al.,in Canada. Eutrophe waters are high in ammonia and phosphorous which can be stripped from the water by seaweed at rates varying from 60% up to 90% of the nutrient input. Macroalgae are able to take up nitrogen from seawater with rates to allow for a biomass increase of ca. 10% day-1. It is well documented that the green alga Ulva is able to remove 90% of the nitrogenous compounds and the red alga Gracilaria up to 95% of dissolved ammonium from fish effluent. By sea cultivating and harvesting macroalgae as biofilters integrated with other shellfish or fish production systems, nutrient polution from these aquaculture systems could be alleviated through a process called IMTA (Integrated Multitrophic Aquaculture) while increasing production and carrying capacity. Production of macroalgae in near-shore sea cultivation can be harvested for the bioethanol market to produce a value added marketable product acting as both an economic incentive and environmental incentive.
However, the focus has shifted and is more and more fixed on alternative protein resources. Seaweed has levels of crude protein between 15-40% of the dryweight and could be an untapped resource for protein production for fed aquaculture. Analysis of the amino acid profiles of the protein fraction shows very comparable or better profiles compared to fish meal, with the advantage that seaweed protein is about 90% of the extracted product while fishmeal contains about 60-70% protein. By using seaweeds and seaweed proteins it will help reduce the pressure and reliance on wild fish stock and some other traditional ingredients and will soon play an important role in the feed and food production. . Development of future large-scale seaweed farms will positively contribute to the growth of maritime sectors and can be a viable alternative for fisherman as existing infrastructure can be applied. It further might enhance employment opportunities in local rural coastal areas in the form of seed hatcheries, seeding units and processing units and create employment opportunities that otherwise would not exist.