Organic algae: Porphyra

Organic Porphyra

Porphyra is the genus of “leaf-like red algae,” whose various varieties are collectively known as nori. They owe their name to their reddish-purple pigments, but they can also range in color from dark green to black. Nori are macroalgae that thrive in seawater and are therefore also known as seaweed. Seaweed is found in practically all the world’s oceans and is increasingly valued as a nutrient-rich food. Although these “plant-like” organisms still play a minor role in Europe, “vegetables from the sea” have a firmly established place in the diets of people in Asia, the coastal regions of North and South America, and the former Soviet Union. In Japan in particular, where around 300,000 tonnes of seaweed now enter the market each year, Porphyra has been valued for more than 1,000 years. In the early 17th century, Tokyo was the center of nori production. Since 2008, it has even been home to a nori museum.

How is nori seaweed powder made?

Porphyra, also known as nori, is primarily known in this country as a dried, paper-thin square used as a sushi wrapper. In Asia, the sheets are also used to wrap meat and vegetables. In fact, there are many different nori products available in Asian and Japanese stores: Yaki-nori (sheets for sushi), Kizami-nori (strips for salads), Ajitsuke-nori (for snacking), and Ao-nori (powder used as a seasoning). For BERTRAND drinkable meals, we need nori in powder form. Cultivating and processing it is a relatively complex process.

1. CULTIVATION

   First, for the aquacultural cultivation of Porphyra, mature “algal leaves” that have been dried for several hours must be placed in shallow tanks filled with seawater. At the bottom of the tank is a substrate made of shells, onto which the leaves release “carpospores.” These settle on the substrate and, under regular illumination at a water temperature of 23–27 °C, grow over several months into filamentous structures. These structures then release the so-called “conchospores.” They are stimulated to do so by blowing compressed air into the water to create strong movement, or by cooling the water temperature to 18–20 °C.
   

   THE FIRST PHASE

2. CULTIVATION

   The conchospores now colonize the intended substrate, usually nets with a cord thickness of between 3 and 5 millimeters. The nets are taken out to sea, to their “nursery.” During the subsequent cultivation phase, the nets are lifted out of the water at regular intervals, exposing them to direct sunlight and allowing them to dry. This prevents unwanted colonization by other, undesirable organisms.
   Once the young algae have reached a certain size, the bundles of nets are cultivated for another 40 to 50 days using various cultivation methods: either they are anchored to poles and remain in the water during high tide before drying out completely at low tide (“pole system”), or they float on buoys in the water throughout the entire cultivation phase (“floating system”).

   THE SECOND PHASE

3. HARVESTING

   After the final 40 to 50 days of cultivation, the first algae are ready to harvest. Our organic nori is painstakingly harvested by hand by divers. This is a very gentle method in which only part of the algae is manually cut at a time, allowing them to continuously regrow. The cut plants are collected from boats while floating during high tide. This prevents damage to the remaining stock. Hand harvesting is a traditional harvesting method. From this point onward, further harvesting cycles can take place every 10–15 days over a period of approximately 5 months.

   DIVERS ARE NEEDED

4. DRYING AND GRINDING

   After the algae have been brought ashore, they are rinsed again in seawater, then cut into smaller pieces and washed in fresh water. They are then spread on bamboo mats, pressed, and dried in drying chambers at a maximum temperature of 45 °C. In some cases, the drying process is still carried out traditionally in the sun.
   To produce nori powder, the dried nori leaves are then gently ground.

   RINSING AND DRYING

But why Porphyra?

Porphyra is a red alga with a high nutrient content. It is especially rich in minerals, particularly iron, potassium, calcium, magnesium, sodium, phosphorus, selenium, and zinc. Among the vitamins, vitamin A, vitamin C, vitamin E, folic acid, and the B vitamins are especially noteworthy.
Nori are also rich in high-quality, easily digestible protein. Those who want to avoid animal-based protein sources will find a good plant-based protein source here. Our vegan BERTRAND drinkable meal also benefits from this. The high fiber content of Porphyra and its content of polyunsaturated fatty acids (omega-3 and omega-6) should not be forgotten. At just 35 kilocalories per 100 grams, the algae are very low in calories. However, two topics are of particular interest in connection with nori:

Nori and iodine

Red algae have a much lower iodine content than brown algae, for example (most brown algae are commonly known as “kelp”). Nori therefore also has a relatively moderate iodine content, meaning that even people sensitive to iodine can generally tolerate it well. Our supplier tests the iodine content. The proportion of nori in BERTRAND drinkable meals is so small that excessive iodine intake is not expected. However, the algae do contribute to the intake of this essential trace element.

Nori and vitamin B12

Vitamin B12 (cobalamin) is found mainly in animal-based foods. It is therefore considered a “critical nutrient” for vegans. Numerous studies have examined the cobalamin content of nori algae. Older studies suggested that nori might contain genuine vitamin B12 in a biologically active form. However, newer measurement and testing methods have shown that the B12 content of nori should be revised downward. Based on current knowledge, vegans should not rely on nori as their primary source of B12. However, thanks to their numerous vitamins, minerals, and proteins, nori make a valuable contribution to a healthy diet—naturally for non-vegans as well.

Flavor?

Then there is the contribution that this sea vegetable can make in terms of flavor. Nori has a slightly sweet, spicy, and savory taste. In Asia, this is described as “umami,” which refers to a fifth taste alongside sweet, sour, bitter, and salty. Because of this distinctive and intense flavor, shredded nori leaves are used as a seasoning in Asia. The good, balanced flavor of our Bertrand products is also enhanced by the Porphyra content.