Seaweed is processed from laver. Porphyra is purple because it contains a special pigment protein called phycoerythrin.

Phycoerythrin is soluble in water, and this pigment protein is unstable, especially easy to be decomposed by heat.

Therefore, when cooking soup, laver without phycoerythrin will lose its original purple color and turn green.

Besides phycoerythrin, laver also contains chlorophyll, carotene, lutein and other pigments.

Among them, the content of chlorophyll is the highest, which replaces the position of phycoerythrin, thus making the leaves "green"

Like chlorophyll in vegetables, it is not toxic. It is normal that those lavers that have been stored for a long time turn green because of the gradual degradation of phycoerythrin.

However, the deteriorated seaweed will appear reddish purple, and the deterioration caused by mold will appear reddish purple, and the reddish purple seaweed cannot be eaten.

Therefore, if laver is found to be reddish purple in life, it is best not to buy it.

Extended data:

Porphyra: Porphyra is crisp and tender after baking, and melts in the mouth. Especially after seasoning, adding seasonings such as oil and salt becomes a particularly delicious "seaweed".

Laver concentrates all kinds of B vitamins in laver, especially riboflavin and nicotinic acid, as well as many vitamins A and E and a small amount of vitamin C.

Seaweed contains about 15% minerals, including potassium, calcium, magnesium, phosphorus, iron, zinc, copper and manganese. This is necessary to maintain normal physiological functions, especially selenium and iodine.

These minerals can help the human body maintain the acid-base balance, which is beneficial to the growth and development of children and also helps the elderly to delay aging.

Seaweed is laver; But laver is not all seaweed.

Rhodophyta, Rhodophyta. Algae are purple or red, composed of single or double layers of cells, and are leaflike, heart-shaped and banded.

The false root fixator at the lower part of laver is attached to the rock. The height can reach 20-30 cm.

The process of androgyny and reproduction is complicated. 1955, scientists in China made clear the life history of laver for the first time, which consists of three stages: laver, filamentous and laver.

The main components of laver are about 50% carbohydrates, about 30% crude protein, rich in vitamins A, B and C, and containing iodine, phosphorus and calcium. It is a commonly used food in China, which is distributed along the coast of China, mainly along the coast of Jiangsu.

There are two kinds of seaweed sold in the market, one is roasted seaweed used for cooking sushi, and the other is called "instant seasoning seaweed". Their raw material is Porphyra yezoensis in laver.

Ten major effects

1, the phycobiliprotein contained in seaweed has the application prospect of lowering blood sugar and anti-tumor, among which polysaccharide has many biological activities such as anti-aging, reducing blood fat and anti-tumor.

The inhibitory rate of effective components on Ehrlich cancer is 53.2%, which is helpful for the prevention and treatment of brain tumor, breast cancer, thyroid cancer, malignant lymphoma and other tumors.

2, seaweed contains vitamin A and vitamin E, and a small amount of vitamin C, which can enhance memory.

3. Minerals in seaweed, such as potassium, calcium, magnesium, phosphorus, selenium, iodine, iron, zinc, copper and manganese, promote the growth of bones and teeth. Can help the human body maintain the acid-base balance of the body.

4. Porphyra is low in calories, but high in fiber, so it is a delicious snack that can be safely eaten.

5, seaweed is sweet and salty, cold, can clear away heat and phlegm, delay aging, and keep skin smooth and healthy. It can effectively prevent nerve aging and regulate the metabolism of the body.

6. Seaweed can prevent and treat peptic ulcer.

7. Seaweed is rich in calcium and iron, which is an excellent food for treating anemia in women and children.

8. Seaweed contains a certain amount of mannitol, so it is a strong diuretic and can be used as an auxiliary food to treat edema.

9. The contained polysaccharide can obviously enhance cellular immunity and humoral immunity, promote lymphocyte transformation and improve organism immunity; Can significantly reduce the total cholesterol content in serum;

10. Alguronic acid contained in seaweed also helps to remove toxic metals from the human body.

References:

Baidu Science Encyclopedia-Seaweed