Types of seaweed: green, brown and red seaweeds

1. Seaweeds are large algae that live in salt or brackish water. Worldwide there are thousands of types of seaweeds that are divided into three groups: green, brown and red seaweeds. Seaweed has a high nutritional value due to the presence of large amounts of vegetable proteins, fibers and essential vitamins and minerals. Moreover, seaweed is low in calories and can be used for various dishes, both dried and fresh. Besides serving as a food source for both humans and animals, there are many other ways to use seaweed, for example as a raw material for medication, cosmetics, bioplastics and biofuel.

Seaweeds are macroalgae

1. Algae are vegetable organisms that live in both fresh and salt water. Algae are distinguished from plants in that they have no roots, leaves, stems or flowers and seeds. The organisms reproduce through spores instead of seeds. Algae are divided into mircoalgae (tiny algae) and macroalgae (larger algae). These larger algae that live in salt water or in the transition between fresh and salt water are called seaweeds. Seaweeds attach themselves by means of an attachment organ (the handhold) to the bottom of the sea or to another solid surface, for example: rocks, coral, oysters. There is also seaweed that does not cling but simply floats in the sea water.

Thousands of seaweed species

1. There are thousands of species of seaweed worldwide. They occur in all oceans and seas and differ greatly in:

Green, brown and red seaweeds

1. All seaweeds contain chlorophyll, a green pigment, which is indispensable for photosynthesis. Photosynthesis is a process in which the pigment present receives sunlight and converts it together with nutrients from water and carbon dioxide (CO 2) into carbohydrates and oxygen. Seaweed grows in this way without making use of food sources from its environment and is therefore photoautotrophic. In addition to the green pigment, the various seaweeds also contain other combinations of pigments, so that the algae differ in color.

The habitat of seaweeds

1. Due to the presence of different pigments, the seaweeds grow at different depths in the sea. All seaweed needs sunlight for photosynthesis. It depends on the pigment composition which part of the daylight is largely needed for the growth of the seaweed. Green algae mainly need the red wave spring of sunlight and this wavelength is difficult to penetrate into the seawater. As a result, green seaweed grows just below the surface of the water. Brown and red seaweeds, on the other hand, need more blue and green wavelengths of daylight for photosynthesis and these wavelengths can penetrate deeper into the seawater. Brown seaweeds grow about two to three meters below the surface of the water. Depending on the clarity of the water, red algae grow from five to a few dozen meters below the surface of the water. The thousands of species of algae are divided into three main groups on the basis of their color and therefore their location: green seaweeds, brown seaweeds and red seaweeds.

Green seaweeds

1. The Latin name for green seaweed is Chlorophyta. They are single or multi-celled macroalgae that grow just below the water surface. Seaweed and sea lettuce are examples of green seaweeds.

Sea lettuce (Ulva lactuca)

1. Sea lettuce is a leaf-shaped seaweed, the leaf is thin and transparent but firm. Sea lettuce resembles the common land lettuce in shape. This seaweed has a sweet, salty, fresh taste and can be used fresh in salads or as a wrap to steam fish. Sea lettuce can also be added dried to dishes as a flavor enhancer.

Intestinal algae (Enteromorpha intstinalis)

1. Intestinal seaweed is a tubular seaweed and thus looks a bit like a intestine. The seaweed has a fresh color and also a fresh mild taste. Intestinal seaweed is suitable for salads or, for example, as a vegetable in a smoothie or soup.

Brown seaweeds

1. The Latin name of brown seaweed is Phaeopyta. These are multicellular macroalgae that live about two to three meters below the surface of the water. This group is the largest group of edible and cultivated seaweeds. Well-known brown algae include: wakame, leash seaweed (sea spaghetti) and kelp.

Beltweed or sea spaghetti (Himanthalia elongata)

1. Beltweed is a thread-shaped seaweed that consists of long strings that can grow to a length of two to three meters. The young shoots of belt weed are therefore also called sea spaghetti. This seaweed has a mild salty taste and can be combined well with fish dishes. Sea spaghetti can also be combined well with grain spaghetti and the sea spaghetti can also be fried as a garnish for soup.

Kelp (Laminaria)

1. Kelp is an order within the brown algae and includes several types of seaweed including sugar seaweed (Laminaria saccharina) and Kombu (Laminaria japonica) Also the largest seaweed in the world, which can be 50 to 70 meters long , belongs to this order: giant kelp.

Wakame (Undaria pinnatifida)

1. Wakame is leaf-shaped and can grow up to two meters long. The seaweed has an olive brown color and is rubbery with wavy edges. The seaweed has a sweet oyster-like flavor and can be used as a flavor enhancer or vegetable in soups, stews or stir-fries.

Red seaweeds

1. The Latin name of red seaweed is Rhodophyta. These are single-celled or multi-celled macroalgae that grow five to tens of meters below the water surface. Well-known types of red seaweed are: nori, Irish moss and dulse.

Nori (Porphyra)

1. Nori, is a collective name that the Japanese use for various types of red seaweeds of the genus Porphyra. Nori is also used for the sushi dish, which consists of a rice snack wrapped in a sheet of seaweed.

Irish moss (Chondrus crispus)

1. Irish moss is a small seaweed that comes in different colors and shapes, usually as flat-branched leaves with graceful curls. The seaweed is widely used as a binding agent for soups and sauces, for thickening pudding and is also suitable for brewing tea.

Dulse (Palmaria palmata)

1. Dulse is fan-shaped and has a flat and tilted leaf that is colored deep red-purple. The seaweed has a full and smoky flavor that goes well with shellfish dishes. The weed can be cooked in various dishes or eaten as a snack by briefly frying the weed in oil.

The cultivation of seaweed

1. Seaweed has been considered a delicacy in Asian countries for decades and in recent years there has also been a growing interest in seaweed in Western countries. In the year 2019, about 5% of the seaweed consumed will be wild harvested through seaweed fishing. Here, mainly brown and red seaweeds are harvested that grow in deeper seawater. The other 95% of edible seaweeds are grown in seaweed farms, mainly in Asian countries such as Japan, China and Korea. The seaweed grows in seas a few meters below the surface of the water on ropes or in large pools.

The possibilities of seaweed cultivation

1. Growing seaweed can be a sustainable solution to the growing demand for food resources in the future. Sea farming does not require agricultural land, fertilizer and extra water as is the case with agricultural cultivation. In 2019, a lot of research is being done into the possibilities of seaweed. In the Netherlands, Wageningen University is experimenting with a large number of companies via a test farm in the North Sea into the possibilities and yields of seaweed. The possibilities of seaweed are many such as:

Seaweed as a food source

1. High nutritional value of seaweed Seaweed is a very healthy food source for humans and is very versatile. Each seaweed has its own taste and nutritional value. The exact values ​​depend on several factors such as the type of weed, the time of harvesting and the preparation (fresh or dried). But all types of seaweed are healthy to eat. Seaweed contains, among other things:

Large number of applications

1. Seaweed is also available dry and / or fresh at health food stores, web stores, supermarkets (Albert Heijn) and Asian stores and has a large number of applications, for example:

Foods with seaweed

1. There are foods with different types of seaweed as an ingredient. As thickeners, carrogen from certain types of red algae (E number 407) and alginates (E number 400-405) from various brown algae are added to foods. Nori crackers are available as well as seaweed chips. There are also wraps of spelled and seaweed, cheeses with seaweed and seaweed burgers for sale. Given the worldwide interest in seaweed, this food range will only grow in the future.