CATDOLL : CATDOLL: Are kelp and laver both seaweed? What are the differences?

Kelp and laver are both algae. The main differences between the two are their different distribution, different nutritional components, and different main values, as follows:

1. Different distribution

1. Kelp

Kelp is a subarctic algae, a species endemic to the North Pacific Ocean, with some kelp distributed in the Atlantic Ocean. Most kelp is distributed in the Northern Hemisphere, while a small amount is also distributed in the Southern Hemisphere. It generally grows on rocks on the seabed in the subtidal zone. Kelp growth is mainly affected by factors such as temperature, light, nutrients, and plant hormones.

2. Nori

Although Porphyra species are distributed in cold, temperate, subtropical and tropical waters, the species diversity is rich in subtropical to temperate waters. The geographical distribution of Porphyra in China also follows this rule, mainly distributed in the intertidal zone from the Yellow Sea and Bohai Sea to the southeast coast. In addition, a few Porphyra species are distributed along the coasts of Taiwan and Hainan Island, and their distribution has regional characteristics. The Porphyra species naturally distributed in the Yellow Sea and Bohai Sea are mainly Porphyra yezoensis, Porphyra serrata and Porphyra semifolia, and those in the southeast coast are mainly Porphyra haitanensis, Porphyra corrugateda and Porphyra longifolia.

2. Different nutritional ingredients

1. Kelp

Kelp is rich in laminarin, and three types of polysaccharides have been found so far: alginate, fucoidan, and brown algae starch. It also contains acidic polysaccharides, fucogalactopolysaccharide sulfate, zosterol, galacturonic acid, laminin, taurine, bifidus factor and other active ingredients. Kelp is a nutritious edible brown algae, containing more than 60 nutrients.

2. Nori

Laver is rich in protein, carbohydrates, unsaturated fatty acids, vitamins and minerals, and has high nutritional value. Laver is one of the seaweeds with the richest protein content. The protein content in laver varies with the type of algae, growth time, location, etc. Usually, the protein mass fraction accounts for 25% to 50% of the dry mass of laver.

3. Main Value Differences

1. Kelp

① For food

The amino acids in kelp protein are complete and in appropriate proportions, especially the eight essential amino acids for the human body, whose contents are very close to the ideal essential amino acid content pattern in protein. In addition to being used as a vegetable, kelp can also be processed into a variety of unique flavor foods.

②For feeding

Adding kelp powder to feed can effectively improve the nutritional structure, reduce feeding costs, increase body weight, increase egg production rate, reduce mortality, and improve the quality of breeding varieties.

③. Used as industrial raw materials to extract fucoidan, mannitol, dietary fiber and sodium alginate from kelp.

2. Nori

Porphyra is nutritious and delicious. It is rich in protein, inorganic compounds, unsaturated fatty acids, vitamins and minerals. The protein content is as high as 25% to 50%, which is of high value in the fields of food and medicine. Porphyra polysaccharides and phycobiliproteins have anti-aging, anti-coagulation and lipid-lowering effects. Porphyra has a strong ability to absorb nitrogen and phosphorus and fix carbon. Its cultivation also plays an important role in the restoration and improvement of shallow sea eutrophication.

Reference source: Baidu Encyclopedia - Kelp

Reference source: Baidu Encyclopedia - Nori

kelp

Laminaria japonica

Kelp is a plant belonging to the genus Laminaria, the phylum Phaeophyceae. It is also known as kelp, kelp, and Jiangbaicai.

Plant morphology: The algae are brown, long and ribbon-shaped, leathery, generally 2-6 cm long and 20-30 cm wide. The algae are clearly divided into the holdfast, the petiole and the leaves. The holdfast is rhizoid-shaped, the petiole is thick and short cylindrical, and the upper part of the petiole is a wide and long ribbon-shaped leaf. There are two parallel shallow grooves in the center of the leaf, and the middle is the middle belt, which is 2-5 mm thick. The two edges of the middle belt are thinner and have wavy wrinkles.

[Origin and Season] Kelp is farmed along the coasts of Liaoning, Shandong, Jiangsu, Zhejiang, Fujian and the northern part of Guangdong Province in my country. Wild kelp can be found on rocks at a depth of 2-3 meters below the low tide line. Due to the influence of temperature differences and light from north to south, the growth and maturity of kelp varies. The maturity of kelp in the same sea area or on the same seedling rope varies, so the harvest period lasts from mid-May to early July.

[Economic Value] Kelp is a vegetable with high nutritional value. Every 100 grams of dried kelp contains: 8.2 grams of crude protein, 0.1 grams of fat, 57 grams of sugar, 9.8 grams of crude fiber, 12.9 grams of inorganic salts, 2.25 grams of calcium, 0.15 grams of iron, as well as 0.57 milligrams of carotene, 0.69 milligrams of thiamine (vitamin B1), 0.36 milligrams of riboflavin (vitamin B2), 16 milligrams of niacin, and can emit 262 kcal of heat. Compared with spinach and rapeseed, except for vitamin C, its crude protein, sugar, calcium and iron content are several times and dozens of times higher. Kelp is a seaweed with a high iodine content. Cultivated kelp generally contains 3-5% iodine, and can reach 7-10%. The iodine and alginate extracted from it are widely used in medicine, food and chemical industry. Iodine is one of the essential elements for the human body. Iodine deficiency can cause goiter. Eating more kelp can prevent and treat this disease. It can also prevent arteriosclerosis and reduce the accumulation of cholesterol and fat.

Sodium alginate in kelp can prevent leukemia and osteomalacia; it also has a hemostatic effect on arterial bleeding, and oral administration can reduce the absorption of radioactive element strontium-90 in the intestine. Sodium alginate has a blood pressure lowering effect. Kelp starch has the effect of lowering blood lipids. In recent years, it has been found that an extract of kelp has anti-cancer effects. Kelp mannitol is effective in treating acute renal failure, cerebral edema, Japanese encephalitis, and acute glaucoma. People with spleen and stomach deficiency should eat less.

Kelp is an export variety, its English name is sea belt, and it is exported to countries and regions such as Japan.

It is also an algae plant. The root-like part is just a root-like structure that serves as a fixation, and the leaf-like part is called a thallus.

Nori

Laver

A general term for Porphyra of the genus Porphyra in the class Protoflorideophy-ceae, order Bangiales, family Bangiaceae, phylum Rhodophyta. Porphyra contains up to 29-35% protein, as well as iodine, multiple vitamins and inorganic salts. It is delicious and can be used to treat goiter and lower cholesterol in addition to being eaten. It is an important economic seaweed. It is widely distributed throughout the world, but mainly in temperate zones. About 70 species have been discovered. The number of naturally grown Porphyra is limited, and the output mainly comes from artificial cultivation. Porphyra haitanensis, Porphyra yezoensis and Porphyra tenera are the main cultivated species.

Brief History As early as 1,400 years ago, the Qi Min Yao Shu of the Northern Wei Dynasty in China mentioned that "all the mountains by the sea of ​​Wudu are full of laver" and how to eat laver. In the Tang Dynasty, Meng Shen's Diet Therapy Materia Medica recorded that laver "grows in the South China Sea, is green, attached to stones, and is purple when dried." By the Northern Song Dynasty, laver had become a precious food for tribute. In the Ming Dynasty, Li Shizhen not only described the morphology and collection methods of laver in his book Compendium of Materia Medica, but also pointed out that laver is mainly used to treat "heat and irritation in the throat" and "all diseases of goiter and mass should be treated with laver regularly." The history of aquaculture is very long. Japanese fishermen may have used bamboo branches and tree branches to collect natural seedlings in the first half of the 17th century, and then used bamboo curtains and natural fiber horizontal net curtains for aquaculture. For a long time, laver seedlings could only rely on natural growth, and the source was limited, so the scale of aquaculture activities was not large. In 1949, British KM Drew first discovered that the fruit spore growth period of laver is very important in its life cycle, which paved the way for studying the source of natural seedlings. Then, Japanese Kuroki Muneshige and Chinese Zeng Chengkui revealed the whole process of laver life history in 1953 and 1955 respectively, laying a theoretical foundation for artificial seedling cultivation. Since then, laver farming has entered a period of fully artificial production, and the output has begun to increase significantly.

Biological characteristics Porphyra has a simple appearance, consisting of a disc-shaped holdfast, a petiole and a leaf blade. The leaf blade is a single or bifurcated membranous body composed of one layer of cells (a few species have two or three layers), and its length varies from a few centimeters to several meters depending on the species. It contains chlorophyll and pigments such as carotene, lutein, phycoerythrin, and phycocyanin. Due to the difference in the proportion of their content, different types of Porphyra appear in purple-red, blue-green, brown-red, brown-green and other colors, but purple is the most common, hence the name Porphyra.

The life of laver consists of two distinct stages: the larger thallus (gametophyte generation) and the tiny filaments (sporophyte generation). The thallus reproduces sexually, with the nutrient cells being transformed into female and male cells respectively. After fertilization, the female cells divide several times to form fruit spores. After maturity, they detach from the algae and are released into the seawater. With the flow of seawater, they attach to substrates such as shells with lime, germinate and grow inside the shells. Grow into filaments. When the filaments grow to a certain extent, they produce conchosporangium branches, which then divide to form conchospores. After the conchospores are released, they attach to rocks or artificially set wooden stakes or net curtains and directly germinate into thallus. In addition, some types of thallus can also reproduce asexually, with the nutrient cells being transformed into single spores, which grow directly into thallus after being released and attached. Single spores are also one of the important seed sources in aquaculture production.

Porphyra thallus mostly grows in intertidal zones, preferring sea areas with strong winds and waves, smooth tides, and rich nutrients. It is highly drought-resistant; the suitable light intensity is 5000-6000 lux, with the characteristics of high light saturation point and low light compensation point, and is a high-yield crop. The adaptability to low temperatures varies with the water content of the algae. When it is quickly dried to 20% water content, it can be restored to vitality after being refrigerated at a low temperature of about -20℃ for several months to 1 year and put back into seawater. The adaptability to the specific gravity of seawater is wide, but 1.020-1.025 is appropriate. The filaments have poor drought resistance and require low light, so they are naturally distributed below the low tide line. When the temperature begins to drop and there is seawater flow, the conchospores are often released in large quantities from 9 to 11 am every day after formation, showing obvious daily periodicity.

The entire breeding process can be divided into two stages: filamentous body cultivation and thallus body cultivation.

Conchocelis cultivation is the process of artificially collecting fruit spores, cultivating conchocelis to form conchospore branches, and finally forming conchospores. It is usually carried out in the nursery room. There are two ways: shell conchocelis cultivation and free conchocelis cultivation. Cultivation of shell conchocelis is carried out from February to March to September. The nursery room is mostly east-west oriented, with skylights and side windows for lighting, or artificial light sources. The cultivation pool can be divided into two types: plane and three-dimensional. The former has a water depth of 20 to 30 cm, and the culture matrix-shells (mostly clam shells) are placed flat on the bottom of the pool; the latter has a pool depth of 50 to 70 cm, and the shells are hung in the pool. When cultivating in spring, select the fruit spores released by excellent laver to make fruit spore water, spray it evenly on the shells, make them drill into the shells, and form conchospores after 4 to 5 months. The main management measures include: ① Adjust the light intensity. It is 3000 lux in the initial stage, and gradually drops to about 500 lux after the formation of conchospore branches; ② Apply nutrient salts. Potassium nitrate and potassium dihydrogen phosphate can be applied in a certain proportion according to different growth stages; ③ Control the water temperature. Make sure that the filamentous plants are not affected by high temperatures in summer and early cooling in autumn during the entire filamentous cultivation period, and ensure that the seedlings are harvested on schedule.

The cultivation of free conchoceles is to place the fruit spores in a glass bottle and let them grow naturally into conchoceles. The ecological conditions during the cultivation period are basically the same as those of the shell conchoceles of the same species of laver. Free conchoceles are mostly used as a breeding method for secondary seedling collection, but as a production method it is still limited to individual regions.

The cultivation of thallus mainly includes several processes, such as collecting shell spores (also known as collecting seedlings), seedling management and vegetable cultivation. Shell spores can be collected in autumn when the seawater drops to a certain temperature, when the shell spores on the shell filaments of Porphyra haitanensis (below 27℃) and the filaments of Porphyra yezoensis (below 20℃) mature and begin to release. Artificially cultivated filaments can be collected indoors or in the sea. When collecting seedlings indoors, synthetic fibers or palm ropes are woven into a net curtain as an attachment matrix and placed in the culture pool, so that the shell spores naturally attach to it; after a few hours, the net curtain is hung in the sea. When collecting seedlings in the sea area, the net curtain and the artificially cultivated filaments need to be placed in a pre-set device in the sea, so that the shell spores naturally attach to the net curtain. Because the release of shell spores has a daily periodicity, the peak of release is mostly between 10 and 11 am, so seedling collection generally needs to be carried out in the morning. In addition, free filaments can also be used to collect shell spores.

The emergence period is from the time when the net curtain is put into the sea to the time when the seedlings can be seen with the naked eye. In order to get strong and full seedlings early, the net curtain must be placed at a suitable tide level, and the algae must be removed and fertilizers must be applied in time. At the leaf-forming stage, reasonable fertilizers must be applied, diseases must be prevented, and the harvest must be timely. The cold storage net technology used in Japan is that when the seedlings grow to 1 to 3 cm, they are quickly dried to a moisture content of 20%, and placed in a -20℃ cold storage with the net curtain for sealed storage for dozens of days to a year before being returned to the sea area for continued growth. This not only helps to avoid the period of disease occurrence, but also can use the cold storage net curtain to replace the net curtain with reduced quality of laver, so that the produced laver remains young and tender.

The cultivation of thallus can be divided into semi-floating and fully floating raft types (see algae cultivation) according to the placement of the net curtain in the sea area. The former is suitable for shallow sea beaches, while the latter is mainly used in deep sea areas. Both methods now use fully artificial cultivation of filaments and artificial collection of seedlings to provide seed sources, which occupy a major position in production. In addition, China also has the vegetable jar type cultivation method, which mainly uses natural shell spores for cultivation on reefs. The unit yield is high, but it is greatly affected by natural conditions and the production is unstable. China has also successfully used cell engineering technology to attach the somatic cells of Porphyra yezoensis and Porphyra haitanensis to the net curtain to cultivate thallus.

Diseases The most common diseases during the cultivation of conchophora are yellow spot disease and mud red disease, which are caused by microorganisms and can be avoided by purifying water quality and stabilizing culture conditions. Common diseases of thallus are red rot and chytrid disease, which can be prevented mainly by reasonable close planting and reasonable harvesting. In serious cases, the aforementioned cold storage network technology can be used.

Harvesting and processing After the thallus has been cultivated for about half a year, the fresh vegetables can be harvested regularly by machine or by hand until the spring of the following year. The fresh vegetables are cut, cleaned, caked and dried to make commercial laver for sale. The dried products can be used as cooking ingredients or processed again into canned food and other foods for direct consumption.

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Nori

Lithospermum truncatum

Porphyra haitanensis T.J.changet B.F.Zheng. Porphyra yezoensis Ueda.

Same as Porphyra suborbiculata Kjellm. Porphyra tenera Kjellm. and many other wild Porphyra

The algae are purple, generally 12-30 cm high, and the cultivated Porphyra haitanensis can grow up to more than 4 meters long.

Liaoning to Guangdong coast.

The edible part of laver contains 10.3 grams of water, 28.2 grams of protein, 0.2 grams of fat, and 0.3 grams of carbohydrates per 100 grams of edible part.

Chemicals 48.3 g, calcium 343 mg, phosphorus 457 mg, iron 33.2 mg, carotene 1.23

mg, vitamin B10.44 mg, vitamin B22.07 mg, niacin5.1 mg, vitamin

Cl mg, iodine 1.8 mg.

Laver is sweet, salty and cold in nature, and has the effects of resolving phlegm, softening hard masses, clearing away heat and promoting diuresis, and nourishing the kidney and the heart.

goiter, edema, chronic bronchitis, cough, beriberi, hypertension, etc.

People with tumors and beriberi should eat it. "Sui Xi Ju Diet" states that it "regulates blood and nourishes the heart." People with weak spleen and stomach should avoid eating it.

They are all seaweed vegetables, you can also call them seaweed.