You eat seaweed without even realising it!
Did you know that you swallow seaweed almost every day? This vegetable from the sea has become an essential ingredient in numerous foods. But where is this seaweed hiding? Olivier Barbaroux, oceanographer at Ifremer (French Research Institute for the Exploration of the Sea) and co-author of the Libris editions book Les Algues (Seaweed), reveals all.
Doctissimo: How long has seaweed formed part of the human diet?
Olivier Barbaroux: In Asia, seaweed has been used for centuries, mainly in Japan, Korea and China. It is used as a vegetable in the daily diet. In the West, seaweed was not really eaten, except for in Britain and Ireland, where a few dishes based on seaweed exist. Seaweed has now begun to invade the western diet in general because it is used as an additive, and in large amounts since the Second World War. The consumption of seaweed as a vegetable is increasingly apparent in Europe today, especially thanks to the growth of Japanese and Chinese communities. Sushi-nori (which is used to make sushi) is the best example of this.
Doctissimo: What nutritional value does seaweed have?
Olivier Barbaroux: Seaweed contains numerous vitamins and oligo-elements. For example, it is rich in betacarotene (an antioxidant precursor to vitamin A), and certain types of seaweed are also very rich in protein, to such an extent that seaweed is thought to address problems of malnutrition in certain countries! It should be noted that in the West, the physicochemical properties of some of the molecules are extracted from seaweed. In fact, we use these for their properties as gelling agents, thickeners and emulsifiers. With its low content in fat and organoleptic properties which are equal to those found in fattening food, seaweed can be used in the form of a powder to replace fatty substances in numerous dishes (sauces, creamy snacks, desserts and charcuterie).
Doctissimo: Could you tell us a bit more quickly about the use of seaweed in the food industry?
Olivier Barbaroux: Seaweed has become an essential ingredient for manufacturers in the food industry. This is a fact. We consume seaweed extracts every day without even knowing it. For example, they are very useful in lighter products, as they replace flour, eggs and butter in order to produce jellies or thicken the texture, without adding calories. Light cheese spreads or “fat free” yoghurts are also made with seaweed extracts. These lighter products often have textures that are two fluid and the seaweed extracts compensate for this by adding viscosity. In ice-creams as well, seaweed extracts are indispensable for achieving a cream which does not form crystals and melts on your tongue. Not to mention charcuterie, especially pâtés, since animal gelatine has come under scrutiny.
Doctissimo: But seaweed is also used in products we would least expect to contain it, right?
Olivier Barbaroux: Some foods can actually contain seaweed, just because this simplifies the manufacturing process considerably and reduces the necessary labour. An example of this would be the patisserie you buy in a supermarket.
To make apple tarts, food manufacturers will not waste their time peeling, slicing and de-seeding thousands of apples! They have found much more practical production methods. Manufacturers reduce the fruit to a puree, then mix it with brown seaweed extract which gels when it comes into contact with calcium ions. They reconstitute the shape of the fruit which can then be sliced uniformly, and these will be spread on the pastry of the tart. It is the same with olives which are stuffed with pepper. These come from a enormous sheet of pepper reconstituted and sliced into strips.
Doctissimo: But how do you know if what you are eating contains seaweed?
Oliver Barbaroux: If you read the packaging, you can find out if the food contains seaweed or not by checking the list of ingredients. All products which contain E400 and E407 have seaweed extracts. But the problem today is that manufacturers can simply indicate the product “conforms to European standards” without specifying details of the additives. This is not complicated to work out though, since as soon as the word “light” is mentioned or if the food has a thick texture, there is a strong chance what you are eating will contain seaweed! But these extracts are often in competition with other thickeners like locust bean gum and modified starch.
Doctissimo: Seaweed has invaded other products as well, hasn’t it?
Olivier Barbaroux: You actually find seaweed in cosmetics too for example. Toothpaste, lipstick and other products can contain it. These can be used in marketing as an advantage (the benefits of the sea) in certain poultices, masks, creams, powders or seaweed bubble bath in thalassotherapy. But their benefits in these products often lack scientific evidence...
Seaweed is also used in medicine; for example, extracts may be used in the coatings of tablets, suppositories, soluble tablets or capsules (they act as protection in order to go through the intestinal wall and release the active ingredients in the guts). Purified agar jelly is also very often used for bacterial cultures or in vitro methods. But seaweed has also been studied for its hemostatic and antiseptic properties.
And, returning to food once more, products designed for pets almost all contain seaweed.
Doctissimo: But isn’t there a risk associated with eating all this seaweed?
Olivier Barbaroux: Seaweed has been used for more than 50 years in food production, apparently without it leading to any problems. You need to make the distinction between consuming seaweed extracts and whole seaweed. While extracts are free from any contamination, seaweed can concentrate pollutants like heavy metals (just like mushrooms or seafood for example). But it should be emphasised that seaweed extracts like alginic acid (taken from brown seaweed) allows the body to detoxify. This was the case during the Chernobyl disaster when the people who had been affected by the radiation were treated with a solution based on alginates.
Get more on this subject…