It's one of the most abundant life-forms on the planet: in fact, the total weight of the world's krill is said to be greater than the combined weight of all the people on earth. These shrimp-like creatures also inhabit one of the world's most pristine environments: the Antarctic, hence those sourced from that ecosystem are claimed to be free from most of the contaminants associated with fish.Aside from these factors, is there anything else that is special about krill oil? Well, yes.
Nutritionally, krill oil is not only an excellent source of the long-chain omega-3 fatty acids EPA/DHA that are associated with cardiovascular health, brain and eye function, anti-inflammatory effects, healthy joints and much more besides but - uniquely for marine oils - krill contains a high proportion of these fatty acids combined with phospholipids rather than as triglycerides. The oil also naturally contains antioxidants, including the pink pigment astaxanthin, as well as vitamins E and A, which makes it very stable to oxidation compared to other sources of polyunsaturated fatty acids.
There is general agreement that the phospholipid content of krill oil - along with its payload of natural antioxidants - sets it apart from other marine sources of long-chain omega-3s. It also serves an important practical purpose, according to leading supplier Neptune, which claims that krill's phospholipids content eliminates "the fishy after-taste and constant reflux", which is "the most frequent side-effect" of fish oil supplements.
But, just as all fish oils are not the same, all krill oils are not the same either.
As Anthony Bimbo, technical consultant at International Fisheries Technology, Virginia, US, points out, there are 80 different species of open-ocean crustaceans that can be referred to as krill, and between 1976 and 2002 some 180 patents were granted in relation to krill and its processing and use. He also estimates that fresh-caught krill contain about 12.5% protein and up to 3% lipids (oil), the rest of the crustacean being mainly made up of water. Processing methods, most of which are proprietary to the companies involved, therefore focus on the economics of production (including the removal of water) and transport to market, as well as ways of preventing degradation, to ensure delivery of the best and highest quality payload of high-value constituents contained in the oil.
Bimbo also asserts that the content and balance of EPA, DHA and other fatty acids in krill oil vary according to the processing method, with more DHA present in the phospholipid fraction and more EPA in the triglyceride fraction. Krill supplier Neptune says that its branded Neptune Krill Oil (NKO) contains by weight at least 30% EPA and DHA and 40% phospholipids. Meanwhile, rival supplier Aker BioMarine says its Superba krill oil contains more than 40% phospholipids, of which 70% are omega-3 phospholipids.
Steve Mellor, technical and applications manager at Croda Europe in the UK says that the composition of the krill oil the company receives from Neptune contains around 30% long-chain omega-3s, including 15% EPA and 9% DHA, along with other omega-3 fatty acids, including DPA. (In spring 2008, Croda entered a 'strategic alliance' with Neptune to market products into the dietary supplements sector that are basically blends of NKO with omega-3 concentrates from Croda's Incromega range.)
Regardless of the form, the literature on the beneficial and therapeutic effects of EPA and DHA is vast. So, because krill oil is a good source of these fatty acids, general marketing claims can be made by association. The literature that specifically supports the benefits of krill oil is, however, far more limited.
Dr Toni Rinow, head of corporate development at Neptune, claims that NKO is the "first and only" clinically proven omega-3 marine phospholipid product on the market, supported by pre-clinical and clinical trials. Meanwhile Aker says it has completed safety and pre-clinical studies and has human studies underway for its Superba krill oil product.
In the US, the FDA has issued a qualified heart health claim for EPA and DHA, and Rinow says "the market is waiting for additional claims" for cardiovascular benefits, while Croda's Mellor says krill oil is "currently undergoing novel food approval within the EU", and that no krill-specific claims have yet been registered under the EU's health claims Regulation.
Krill oil's potential in functional foods is enhanced, says Rinow, by its "exceptional stability and antioxidant potency". She points out Neptune's recent agreements with Nestlé and Yoplait, "paving its entrance into the global functional food market". With EU novel foods approval expected imminently, the European market also seems poised for a major growth spurt.
In the US, NKO recently gained entry into the Walgreen's retail drug-store chain through distributor Schiff, as a named constituent of Schiff MegaRed. Along with another recent deal with Costco, Neptune sees this move as an "opportunity to generate high sales growth"
Meanwhile Aker, with a new "super-trawler" (left) now deployed, is about to make ambitious launches with its Superba krill oil, first in Norway, then in the US and the Asia/Pacific region."
There are now the beginnings of differentiations around krill oil products. "Customers are now searching for more than omega-3," says Steve Mellor, "something a little different that can satisfy consumer demand. Croda's Essentially range was born from here." This move, made in joint venture with Neptune, can be seen as a further progression into differentiated products for the supplements market.
Another form of differentiation is Enzymotec's recent launch (September/October 2008) of Crill - an oil based on vegetable-sourced phospholipids and said to be "richer in DHA than krill oil", and significantly less expensive. Enzymotec's chief executive Dr Ariel Katz has called it a "new biofunctional ingredient"
Since they can determine both price and functionality, production methods for krill oil are also likely to remain in sharp focus. Aker, for example, is claiming a unique harvesting method, as well as complete processing - producing krill meal, krill oil and a new krill powder - on board its new trawler. The company has said that, in addition to its Superba krill oil product, it will also produce krill powder and tablets on board the vessel for marketing in the US in the first quarter 2009.
It has been estimated that the 'southern ocean' contains some 7,000Mt of krill but, as Bimbo points out, they are the staple food of many species of the largest mammals on earth - whales - not to mention penguins, sea birds and other marine creatures. However, he puts the actual production of krill oil at present at "probably less than 500t per year"
But is all this about to change? About a year ago, Aker BioMarine announced it was building two 'supertrawlers' capable of catching and processing up to 200,000t of krill between them - possibly equating to 25,000-30,000t of dried krill or about 2,500t of krill oil, according to Bimbo.
The company recently announced the commissioning of both vessels, but has said that one of them - the Saga Sea - will be sufficient for its current needs. The trawler uses a patented harvesting technique that brings the krill on board alive, making it possible to process them freshly on the spot, thereby "gently extracting" the bioactive components. Aker says it is cooperating with WWF Norway to ensure the continued sustainable management of resources, and that its 'eco-harvesting' technology successfully prevents by-catches of other species.
The current limit set for the annual krill harvest is 4Mt, which is many times the current catch, and equivalent to about 50,000t of krill oil, according to Bimbo's multipliers. Quite substantial room for growth, then.