Is seaweed vegetables or not vegetables

Vegetables from the sea

A good source of biologically high quality protein, long-chain omega-3 fatty acids, vitamin B12 and iodine - sounds like fish, but algae are. Sea vegetables have been part of Asians' food culture for thousands of years. As a food trend, it has now also spread across Europe. What does the “food of the future” have to offer?

What evolved long before the time of the dinosaurs is now mainly produced in large-scale marine cultures in Indonesia, the Philippines, South Korea, Japan and China. There the author praised Sze Tou as early as 600 BC. Algae as a suitable food for honorable guests and kings. From a global perspective, the annual algae harvest is steadily increasing and was estimated at around 14.5 million t in 2007. The main reason for the growth is its use as animal feed and as a binding and thickening agent in the food industry. However, the majority is still eaten straight away. Even though algae are becoming increasingly popular in Europe due to the influence of Asian cuisine and speculative health claims, the Asian region is way ahead of us when it comes to consumption. A comparison shows: In Europe 70 tons of dried algae are eaten every year - in Japan 97,000. In the meantime, European cuisine has picked up on the trend and also enriches local menus with sea vegetables. The preparation options are varied. They are used in soups, salads, casseroles and smoothies, as a pesto, side dish or spaghetti.

Worth knowing

Algae are botanically classified according to their size. Macroalgae can grow up to 50 meters long. Microalgae are up to a millimeter in size. Only macroalgae are eaten. They are also called seaweed or seaweed. They are further classified according to their color in brown, red and green algae.

Vegetable nutrient exotic

A good source of biologically high quality protein, long-chain omega-3 fatty acids, vitamin B.12 and iodine - sounds like fish, but is algae. Their ingredients are one of the reasons why sea vegetables are being traded as the food of the future. The protein content of nori algae, for example, is comparable to that of soybeans.
Algae are low in energy and fat and rich in soluble and insoluble fiber. The little fat is high quality: eicosapentaenoic acid and alpha-linolenic acid contribute to a favorable omega-3 / omega-6 ratio. Algae are also rich in beta-carotene, B vitamins and vitamin C as well as the minerals calcium, potassium, magnesium and the trace elements iron, zinc, copper, manganese and iodine. In addition to animal foods, they also contain vitamin B that is useful for humans12. However, this does not apply to all species - only seaweed of the genus Enteromorpha (e.g. sea lettuce) or porphyra (e.g. nori) contain significant and usable quantities.

It all depends on the dose

Despite their nutrient density, the contribution of algae to the overall supply is limited. There are several reasons for this. Algae are a natural product and are therefore subject to pronounced seasonal and regional nutrient fluctuations. The amount consumed is also small: a sheet of nori seaweed weighs around 3 g. With a normal serving of maki sushi (18 rolls), that's just 6 g of seaweed. With regard to the sometimes high iodine content, it makes sense to use it sparingly, because people in areas of iodine deficiency such as Austria are more sensitive to an iodine excess than the average Japanese. Due to our usually low iodine intake, a prolonged iodine oversupply can more easily lead to a disruption of thyroid function. Particularly small children, pregnant women and the elderly need to be careful. Brown algae such as kombu should be avoided by people who already have thyroid nodules, given their high iodine content.

Worth knowing

When preparing algae you should follow the manufacturer's instructions, because the iodine content in algae can vary between
1-4600 µg / g dry goods vary. The German Nutrition Society (DGE) sets a maximum value of
500 µg iodine / day is specified.

As a natural component of marine ecosystems, algae not only filter valuable minerals, but also toxic substances such as heavy metals. The problem with this is that most of the edible seaweed is grown in open seawater cultures. The steadily increasing marine pollution therefore also affects the load on the algae. The levels fluctuate, but studies have shown that they do not pose a risk to humans.

Nutritional content of popular algae (per 100 g dry matter):

Protein (g)31,419,87,511,6
Protein quality189,695,965,980,9
Fat (g)2,84,51,01,4
EPA (% of fat)20,913,216,242,4
n6 / n3 ratio0,6:10,5:11,3:10,3:1
Dietary fiber (g)49,845,936,062,3
Insoluble fiber2 (G)30,016,011,831,3
Iodine (µg)2.64016.300293.40026.200

1 Specified as Essential Amino Acid Index (EAAI) ² determined as Neutral Detergent Fiber (NDF)

Arame to Wakame

At least 145 different types of algae end up on plates around the world. The most famous representatives are:

Arame (Eisenia bicyclis): The brown alga is also called lake oak and has a sweet taste with a pinch of sea. It is used in soups, salads or as a vegetable. It stands out on the plate with its dark color. Beware of the amount, its iodine content is high.

Dulse (Plamaria palmata): The nutty-tasting ragweed is also traditionally eaten in European countries such as France, Great Britain and Ireland. The red alga is served fresh as a spinach-like side dish. Your iodine content is mediocre.

Hijiki (Hizikia fusiform): The brown alga has a special aroma. The taste is reminiscent of fish with a note of anise. Their dark hue can, for example, be presented attractively as a salad in contrast to grated carrots or avocado. It has a medium iodine content.

Kombu (Laminaria sp.):When air-dried, the red alga forms the sugar alcohol mannitol and is therefore also called sugar kelp thanks to its taste. It is also the basis for the famous dashi broth - a Japanese fish stock and an important part of traditional cuisine. Due to its very high iodine content, kombu should only be used as a spice.

Sea lettuce (Ulva lacuca): The green alga looks like a lettuce and that's how it got its name. It also grows on the coasts of northern France and Spain. Sea salad is available fresh or pickled in salt. Its iodine content is low.

Nori (Porphyra sp.): Less known than his involvement in sushi is that nori is not a special seaweed. The starting products are different red and green algae - mostly of the same species Porphyra. They are dried, roasted and made into paper-like leaves. Its taste is mild and the iodine content is comparatively low.

Wakame (Undaria pinnatifida): As a classic of Japanese cuisine, brown algae is the most widely consumed seaweed in Japan alongside nori. In it lies the secret for the sea flavor of the miso soup. Wakame is also eaten with fish or briefly blanched as a salad. Despite being classified as a brown alga, it has an intense green color. Your iodine content is mediocre.

Kitchen tips for dealing with algae:

  • Algae are usually sold in dried form. Once opened, they should be kept airtight so that they retain their aroma.
  • Store fresh sea vegetables in the refrigerator and only keep for a few days.
  • If algae taste too intensely like the sea, they can be soaked in water for a few hours or briefly boiled. This not only reduces their aroma, but also the iodine content to a tenth.
  • Dried algae should also be soaked in cold water when preparing them as vegetables - this improves their consistency.
  • Cooked algae can be frozen and reheated without any problems.


Algae contain a mix of valuable nutrients. With the usual consumption quantities, however, the contribution to the overall supply is limited. Their high iodine content is an exception. Those who pay attention to the amount consumed do not have to fear an overdose. Risk groups such as children, pregnant women, the elderly and people with thyroid disorders should avoid brown algae that are particularly rich in iodine such as kombu. From a culinary point of view, there is a new world of creations to discover with algae - it doesn't always have to be Asian. Combinations with traditional cuisine can surprise even those who don't like local algae.



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