What is the Alga Nori
What we commonly call Nori, is a red alga belonging to the genus Porphyra (Bangiophyceae), within which approximately 70 species are recognized. In particular, the Nori seaweed refers to some very specific species, among which they stand out for their notoriety Porphyra yezoensis And Porphyra tender, sometimes called Laver (England, USA, Canada), Purple Laver (Great Britain and Ireland), Karengo (New Zealand), Kim (Korea), Nori (Japan) and Zicai (China).
Cultivation
Nori seaweed has been cultivated in Japan and the Republic of Korea since the seventeenth century, when natural stocks were no longer able to meet demand. Today, Porphyra crops are the subject of one of the largest aquaculture industries in Japan, Korea and China. Due to the significant economic importance, and the benefits to human health, Nori seaweed crops are beginning to extend beyond the borders of origin. In fact, species of the genus Porphyra grow in most part of the intertidal zones of the globe, also extending into some subtropical and subarctic regions, as confirmed by historical findings that tell how these algae represented an "important source of sustenance for the indigenous populations of Alaska, Canada, Hawaii, New Zealand and part of the British Isles.
Nutritional properties
Nori seaweed is among the most nutritious macroalgae, with a protein content of 25-40%. Rich in iodine (100-300 µg per gram) and low in fat and carbohydrates, nori seaweed is known for its richness in minerals and vitamins A (in the form of Beta-Carotene), C, PP (niacin) and folic acid.
It should be noted that the drying processes to which it is subjected significantly reduce the content of thermolabile vitamins, such as C, originally present in a concentration higher than that of oranges. The most important amino acid in quantitative terms is arginine.
Even the sodium content, originally high, tends to decrease in the washing processes from which the Nori seaweed is produced. The marked sapidity of the product, in addition to the certainly not negligible sodium content, is linked to the particular amino acid profile of the " Nori seaweed, where three amino acids stand out: alanine, glycine and glutamic acid. The latter, combined with sodium, forms monosodium glutamate, a well-known flavor enhancer that stimulates particular taste receptors: umami.
As far as the edible part is concerned, Nori seaweed is digestible for about 75% of its weight. The remaining percentage is linked to the generous content of fibers, especially soluble ones.
Vitamin B12
Naturally, the nutritional values are quite variable, in relation to the species of origin, the environmental conditions in which the seaweed is grown and the industrial processes to which it is subjected.
In any case, among the characteristic vitamins of Nori seaweed, a leading role is played by vitamin B12, often lacking in the vegetarian's diet. Numerous studies have investigated the real bioavailability of vitamin B12 contained in algae, reaching the conclusion that in these foods, its bioavailability is very low, to say nothing. In any case, as regards the Nori seaweed in particular, numerous scientific evidences underline how the vitamin B12 contained in it is not only well absorbable, but also - at least partially - metabolically active. Unlike blue algae (cyanobacteria such as spirulina algae and Klamath algae), Nori algae therefore seems to represent an excellent source of vitamin B12 for vegans.
Taurine and Betaine
In the "Nori algae there are also the amino acid taurine - which contributes, together with the soluble fibers, to reduce the cholesterol levels in the blood, as well as to regulate the liver activity - and the red fluorescent pigment r-phycoerythrin, used as a marker in medical diagnostics.
The betaine content contributes to reducing the cardiovascular risk associated with high plasma levels of homocysteine, typical of those who follow a diet rich in meat and low in seasonal vegetables and fruit.
Benefits
There are numerous health benefits attributable to the regular consumption of Nori seaweed, linked to the abundant presence of nutrients that are friendly to health (including iodine, selenium, beta carotene, antioxidant vitamins, betaine, alginates, iron and omega three fatty acids, in particular EPA). Providing a simple list of these "therapeutic" virtues would still be a stretch: remember that the diseases listed below have a "multifactorial origin, so neither a particular diet, nor the consumption of a" simple "food can guarantee absolute protection against them. However, the consumption of Nori seaweed can be useful for patients suffering from hypercholesterolemia, hypertriglyceridemia, pre-diabetes, thrombosis, peptic ulcer, malnutrition, stress and difficulty concentrating, constipation, hypothyroidism due to iodine deficiency, inflammatory diseases, overweight and obesity, as well as playing a possible preventive role in the development of heart disease and some types of cancer, such as colon and breast cancer.
