Dulse, also known as dillisk (Palmaria palmata) is an edible red seaweed that has been a traditional food in northern Europe and North America for centuries. Dried dulse makes for a great seasoning or snack; alternatively, soak it in water for other uses.
In addition to having a very subtle taste of the ocean, the savory-tasting dulse is reminiscent of nuts and is somewhat salty. In dried form, the seaweed has a crispy yet soft texture. It is not necessary to cook dulse before eating or using in recipes.
Dulse can be prepared in the same way as leafy vegetables. Given its natural ability to enhance flavor, it is a versatile addition to many dishes. For example, it can be used to season salads, soups, rice dishes, noodles, and potatoes or as an ingredient for hearty bread recipes. You can also fry dulse until crispy in the pan to serve as a tasty side dish. In dried form, dulse is a very popular snack and goes well with nut and dried fruit mixes. Powdered or flaked dulse can also be used as a light seasoning.
Depending on how you want to use it, soak dried dulse in water for about 5 minutes beforehand. This increases its weight and volume about sixfold.
Dried dulse can be purchased in fine food stores, on the Internet or in organic health stores. Depending on its quality, the price can vary from €10 to over €30 per 100 g. In addition to dried dulse leaves, flakes or powder are also available. However, it should be noted that 40 grams of dried dulse are equivalent to 400 grams of fresh seaweed. Labels such as raw, air-dried, sustainably harvested, pesticide-free, and certified sustainable production are good indicators that the product is of higher quality.
When buying seaweed, be sure to choose products that have the iodine content stated on the packaging. Keep in mind that these are average values, as the iodine content of seaweed is not standardized and can therefore vary greatly.
Dulse grows on coastal, rocky terrain and is native to the Atlantic, from Portugal to Iceland, the North Sea, and the Baltic. It is also found in the Pacific from Korea to Russia, Alaska, and Canada. Wild dulse is harvested between the summer and autumn months. At low tide, the younger algae are handpicked and then thoroughly cleaned.
Dried dulse keeps for up to several months if stored in a cool, airtight, and dry location.
Dulse is high in carbohydrates and protein and has a low fat content of 2 %. It has significant mineral levels of about 6 %. In addition to the calcium, magnesium, iron, and iodine dulse contains, the B complex vitamins and vitamin C deserve special mention. According to the Austrian nutrient tables (Österreichischer Nährwerttabelle, ÖNWT), dulse contains 317 µg iodine per 100 g.2 The German Federal Institute for Risk Assessment (BfR) suggests 1500–5500 µg iodine per 100 g for dulse (Palmaria palmata).3 The recommendation of the German Nutrition Society (DGE) of 200 µg of iodine per day for adults should also be taken into consideration.4
Some studies demonstrate the antioxidant potential of dulse peptides. Its use as a health-promoting food is under discussion.5,6 In addition, anti-inflammatory components have been found in water extracted from dulse.7
As marine algae are naturally rich in iodine, excessive intake can lead to thyroid dysfunction and result in severe health problems. In dried algae and seaweed products, iodine concentrations of between 5 and 11,000 mg per kilogram dry weight are possible, which is why the BfR recommends setting standardized maximum levels in the European Union (EU). As a mandatory requirement, manufacturers and suppliers of seaweed products should include this information. The BfR states that any dried seaweed products containing more than 20 milligrams of iodine per kilogram should not be sold as they can be harmful to health.8
The recommended iodine intake depends on whether the countries concerned are iodine deficient (such as Germany) or are regions where the population gets sufficient dietary supply, for example, in the United States or Asia. In Germany, a maximum daily iodine intake of 500 µg is considered safe, even for people who are sensitive to iodine exposure. A “normal” diet does not exceed this value.8
The possible remains of shellfish between the leaves of dulse can trigger allergic reactions. For this reason, it is very important to clean the seaweed well.
Kainic acid is a marine neurotoxin that occurs naturally in seaweed. Its chemical structure is very similar to that of domoic acid, also a marine biotoxin, which causes amnesic poisoning. Kainic acid is also thought to have a neurotoxic effect. Unfortunately, the BfR has not been able to make any assessment of its health effects because of the lack of data on toxicity and exposure levels.9However, according to the German Bundesverband Aquakultur (Federal aquaculture association), there is no recorded case of death or serious illness caused by the consumption of dulse.10
Dulse (dillist, dilist, red dulce) is most commonly found in the rocky coastal areas of the Atlantic and Pacific, growing on stones or other algae. It also grows in cool waters from northern Portugal to the Baltic States and Iceland, as well as on the coasts of Russia, Arctic Canada, Alaska, Japan, and Korea. Dulse is traditionally eaten in Scotland, Norway, Iceland, and Canada.
Dulse (Palmaria palmata) belongs to a subgroup of the red algae (Rhodoplantae) and is the only type of Palmaria that is widespread in the Atlantic Ocean. This perennial and edible alga is known as “dulce” in France, “dulse” in Great Britain and Ireland, and “söl” in Iceland.1
Dulse is reddish-brown to purple-red in color with fronds that vary in shape and measure between 5 and 50 centimeters. Emerging from a disc-shaped base (discoid), the stipe (stalk) of the dulse plant expands to grow smaller leaves that have a leathery texture. These leaflike fronds take on a wide variety of shapes with a width between 8 and 30 centimeters.1