A Detailed Guide to the Benefits and Effects of Nori, Its Dietary Contraindications, and Common Varieties

Nori is a dish that appears very frequently on everyone's daily dining table, generally used to make nori egg soup or nori rice rolls. The benefits and effects of nori are also too numerous to count, so do you know what the dietary contraindications of nori are? As for the common varieties of nori, how many kinds are there?

I. The Benefits and Effects of Nori

1. It is rich in nutrients and has a very high iodine content, and can be used to treat “goiter” caused by iodine deficiency. Nori has the function of softening hardness and dissipating nodules, and is also useful for other stagnant accumulations and masses;

2. It is rich in choline and calcium and iron, can enhance memory, treat anemia in women and children, and promote the growth and health of bones and teeth; it contains a certain amount of mannitol and can serve as an auxiliary food for treating edema;

3. The polysaccharides contained in nori significantly enhance cellular immune and humoral immune functions, can promote lymphocyte transformation, and improve the body's immunity; they can significantly reduce the total serum cholesterol content;

4. The active ingredients of nori have an inhibition rate of 53.2% against Ehrlich carcinoma, and help prevent and treat tumors such as brain tumors, breast cancer, thyroid cancer, and malignant lymphoma.

II. Dietary Contraindications of Nori

1. It should not be eaten in excess;

2. Those with poor digestive function or a constitution with spleen deficiency should eat it with caution;

3. It is not recommended for people with breast lobular hyperplasia, those with spleen-stomach deficiency cold, those with abdominal pain and loose stools, and patients with various tumors.

III. Common Varieties of Nori

1. Tan nori (Pyropia haitanensis): Tan nori is a seaweed unique to China that can be artificially cultivated. The thallus is dark purple-green with a slight brownish tinge, lanceolate, subovate, or long ovate, with a heart-shaped, round, or wedge-shaped base, and edges that are slightly wrinkled or not, with sparse serrations. Tan nori has a long history in China and was first named after Haitan Island, the main island of Pingtan County, Fujian Province. As early as the third year of the Taiping Xingguo era of the Song Dynasty, it was listed as a tribute item. At present, it is mostly cultivated along the coasts of Fujian and southern Zhejiang.

2. Striped nori (Pyropia yezoensis): The thallus of striped nori is bright purplish red or slightly blue-green, ovate or long ovate, generally 12-70 cm or more in height, with a round or heart-shaped base and wrinkled edges, with cells arranged neatly and smooth without serrations. The chromatophore is stellate and located in the center; the basal cells extend into an ovate or long rod shape. It is monoecious, and the leafy thallus can form monospores for vegetative reproduction. It is a common species along the coasts of northern China and the main cultivated algae north of the Yangtze River. It is rich in protein, polysaccharides, and vitamins, and can be used as food or medicine.

3. Round nori (Pyropia suborbiculata): Round nori is a plant of the genus Pyropia in the family Bangiaceae. The thallus is purplish red, round or kidney-shaped, sheet-like, and membranous, 6-10 cm wide and 3-15 cm high, with a heart-shaped base and clearly serrated edges. It is monoecious. It usually grows on rocks in the middle and high tidal zones, with its peak growth period from December to April of the following year.

4. Long nori (Pyropia dentata): Long nori is a plant of the genus Pyropia in the family Bangiaceae. The thallus is pale purplish red or purplish red, sheet-like, and membranous, 15-100 cm long and 2-10 cm wide, with a round or heart-shaped base, few wrinkles, and serrated edges. It is monoecious and usually grows on rocks in the middle and high tidal zones.

5. Sweet nori (Pyropia tenera): Sweet nori is a plant of the genus Pyropia in the family Bangiaceae. The thallus is mostly ovate, lanceolate, or irregularly round, 20-30 cm high, with large ones reaching 60 cm, and 10-18 cm wide, with a few reaching more than 30 cm. The base is wedge-shaped, round, or heart-shaped, and the edges are more or less wrinkled, smooth, and without serrations. The thallus is relatively thin, only 20-33 micrometers thick.