The so-called shark's fin is the fine filamentous cartilage in the fins of sharks. Sharks are cartilaginous fish, and their fin bones are shaped like vermicelli, but they are more crunchy than vermicelli when you bite into them and have a better taste. From the perspective of modern nutrition, shark fins (i.e., cartilage) do not contain any nutrients that the human body is prone to lack or high value, so eating shark fins is a cultural phenomenon unique to China. As China is located in the temperate zone with cold winters, frequent droughts and floods, inland areas are relatively remote from the sea, so the food preservation technology is very developed, drying and hydroponics process is one of the most important methods. Dried shrimp, sea cucumber, abalone, shark's fin, bird's nest, squid, shiitake mushrooms, yucca slices, yellow flowers, fungus are examples of the application of this method. During this process of drying and hydration there are physical and chemical changes, and the texture and flavor of the food is sometimes superior to that of the fresh product, and some harmful substances are also removed. The preparation and cooking of shark's fin is so complex and specialized that amateurs are hardly allowed to touch it, which not only justifies the high price of shark's fin soup, but also establishes the status of eating shark's fin as a Chinese cultural wonder. If these techniques are lost because shark fins are not eaten, it would be an incalculable loss to Chinese civilization.

Shark's fin is one of the eight delicacies of the sea, with bird's nest, sea cucumber and abalone known as China's four "delicious". It is made from the shark's chest, abdomen, tail and other parts of the fin fins cut into silk dried, not only is the famous "delicious food", but also said to have a variety of therapeutic value. Chinese tradition believes that eating shark's fin can benefit the vital energy, clear the mind, remove phlegm, diuretic, appetizer, moisturize the skin and nourish the face; it can nourish the five viscera, grow the waist strength, relieve the depression of the liver, activate the vitality of the blood and moisturize the muscles.

Bird's nest

Bird's nest is the nest of the seabird swiftlet. It is mostly built on the cliffs of tropical and subtropical islands, surrounded by rolling waves, with blue sky and white clouds above. Swiftlets start to make nests in the spring, its mouth can secrete a kind of gelatinous saliva, spit out by the sea breeze blowing dry, it becomes translucent and slightly light yellow material, which is the main ingredient of the bird's nest. The swiftlet uses this saliva to make a nest with delicate seaweeds, down feathers and soft plant fibers, which is what we call "bird's nest". Bird's nest is a precious delicacy, but also valuable medicinal herbs, have the effect of tonifying the lungs and nourishing the yin, the main treatment of deficiency cough, coughing up blood and other diseases.

Bird's nest, as the name suggests, is the nest of a swallow. But it is not the nest of an ordinary swallow, but a special kind of swallow ...... Golden Swallow's nest.

The Golden Swallow belongs to the Ornithischiaceae, the family of Rain Swallows. It is a migratory bird that flies from Siberia and other places to the natural caves along the tropical coasts from December to March every year to breed its offspring. The swiftlet is smaller than the swallows we usually see, with grayish-brown back feathers with golden luster, pointed and long wings, and four toes growing forward. This swallow has a well-developed mucus gland in its throat, and the saliva it secretes can be condensed into a solid in the air, which is the main material for them to build their nests. Swiftlets lay eggs in March and April every year. Before laying eggs, they fly in the sea and high altitude every day, sometimes up to thousands of meters, through the clouds and fog, sucking the rain and dew, ingesting insects, seaweed, silverfish and other things. After digestion, they burrowed into the deep cracks and caves of precipitous, cool, and high-altitude cliffs to spit and build their nests. It takes about 20 days to build.

The swiftlet nests are half-moon shaped, shaped like human ears, with a diameter of 6 to 7 centimeters, thick base and thin walls, weighing about 10 to 15 grams. The outer part of the nest is neat and tidy, while the inner part is rough and has the appearance of a loofah network. The whole bird's nest is white, crystalline and elastic, attached to the rocky cliffs. It is also known as the "rare and famous medicine" and "Oriental treasure".

The first nests built by swiftlets are made of a large amount of mucus secreted from their throats, which is pure in texture and not attached to a single hair, and this kind of bird's nests are of the best quality and are the finest among all bird's nests. During the feudal imperial era, it was often chosen as a tribute to the emperor, hence the name "Official Bird's Nest".

After the bird's nest collector seized the opportunity to take away the bird's nest, the swiftlet had to make a nest for the second time. Because of the close proximity of the egg-laying period, the swiftlet has a plump body and more gelatinous material in its throat, and its nest is relatively large and fat, but because of the time constraint, they bring in feathers and grasses ....... However, due to time constraints, they bring in feathers, grass and throat gelatinous material to build nests again, which is relatively rough and contains more impurities and poorer nutrients. The bird's nests harvested at this time are called "Hairy Bird's Nests".

With egg laying imminent, the swiftlet has to build its nest for the third time. At this time, the swiftlet's throat is forced to spit out blood-like mucus, some of which is even bright red in color, and the nest it builds can be described as a blood-soaked condensation. At this time, the people who pick the swallows should not pick them again so that the swiftlets can give birth to children, and then pick them again after the mothers fly away from the nests with their milk swallows, which is called picking the "old nest", also known as picking the "blood swallows".

There is another kind of bird's nest that is moisturized by the red liquid seeping out from the red rock wall attached to it, and the whole body becomes dark red, also called "Blood Bird's Nest" or "Red Bird's Nest", which contains a number of minerals, is good in nutrition, and with very little production, it is regarded as the treasure of bird's nests.

Climbing the rock wall to collect bird's nests is a very hard and dangerous labor. The collectors carry a bag on their backs and climb between the steep cliffs, as if they were monkeys, stepping on the hollows, picking at the cracks and searching around for the collectors. They are as light as a swallow, bold as an eagle, and sometimes their hands and feet are in the shape of a "big", attached to the rock wall; sometimes with the help of ropes such as swinging in the canyon. Every move, the heartstrings, in case of loss, fell into the ravine, to be shattered. So the bird's nest is expensive, in addition to its own really nourishing effect, there is also a collection of life-threatening factors within the bar.

Bird's nest is a rare and expensive thing, mainly produced in Java, Sumatra, Thailand, Vietnam, Japan and other places. China's Sichuan, Fujian and other provinces are also produced.

Legend has it that the first person to eat bird's nest in China was the Ming Dynasty navigator Zheng He. Zheng He's ocean-going fleet encountered a big storm at sea, anchored in the Malay Archipelago at a deserted island, food shortage. He accidentally found bird's nests on the rocky cliffs, so he ordered his men to pick them, clean them, and then stew them in water to fill up their stomachs. A few days later, each member of the crew had a rosy face and was quite energetic. So the fleet returned home with some offerings to Ming Chengzu. In fact, before this, the Yuan Dynasty Jia Ming (1279 AD - 1368 years) of the "dietary instructions" book, said there is "bird's nest, taste sweet and flat, yellow and black moldy toxic, do not eat" records. In the Qing Dynasty's Kangxi year, "Tiao Dingji" recorded dozens of "on the menu", the first is bird's nest.

There are three major types of bird's nests, namely, the natural Cave Bird's Nest, the artificially raised Bird's Nest built indoors, and the processed Bird's Nest. There are also artificial bird's nests made from seaweed and fake bird's nests made from starch. This kind of counterfeits can almost be confused with the real ones, so the first thing you need to do is to distinguish the real ones from the fake ones, and then classify them into different categories and grades.

There are many ways to cook bird's nest, and the most popular one is to cook the famous dish "Bird's Nest in Clear Soup". Before cooking, the bird's nest will be raised, and its methods include alkali hair, evaporation and soaking. The soaking method is to soak the bird's nest in cool water first, and when it swells and foams through, use a white porcelain plate with a rim to fill it with water, and gently fish out the bird's nest and put it in the plate (because the bird's nest and the plate are white, there are hairs and other impurities easy to find, and select the bird's nest hairs, impurities, and deterioration with a sharp-tipped ingot. Be sure to select the bird's nest cleanly and gently, so as not to mess up the shape or break the bird's nest threads. After selecting the bird's nest, wash it with cool water, put it into the soup and stew it slowly with mild fire, then put ham, chicken, quail and pigeon's egg into it. Its flavor is fragrant and wonderful. If you eat sweet, you can also use rock sugar and fresh coconut milk or chrysanthemum, white lotus with stew, it is a unique flavor. With the garden food list" said: "this thing to clear, can not be greasy mixed; this thing to the text, can not be martial arts string of", "to soft with soft, to clear with clear", is to follow, otherwise it will be a good thing shall not be delicious. If you don't want to use the bird's nest, you can store it in the refrigerator and change the water once or twice a day.

Bird's nests have a high edible and medicinal value. According to the "Food Composition Table" compiled by China Institute of Medical Science and Hygiene and "Bird's Nest Examination" analyzed by Prof. Guan Peisheng and Prof. Wang Runxiang of Department of Biochemistry, The Chinese University of Hong Kong, bird's nest contains 49.9% protein and a large number of biologically active protein molecules as well as vector fats and phosphorus, sulphur, calcium, potassium and other ingredients, which have the effect of nourishing Yin and restoring the strength of the human body. According to the Qing Dynasty Zhao Xuemin's "Gleanings from the Compendium of Materia Medica", "Bird's nest nourishes the lung yin, transforms phlegm and stops coughing, and can be cleaned up to regulate deficiency and laboriousness of the holy medicine. All the diseases due to lung deficiency can not be cleaned down the line, with this one can be cured." According to the research of relevant experts, bird's nest contains epidermal growth factor and auxiliary cell division components, which help stimulate cell growth and reproduction, human tissue growth, cell regeneration, as well as the immune function of the cell hair have a promotional effect. In addition, bird's nest also contains a large number of mucin, glycoprotein, calcium, phosphorus and other natural nutrients, which can moisten lung dryness, nourish kidney yin, and replenish the effect of deficiency, which can enhance the body's resistance to diseases, and help to resist colds, coughs and flu. Therefore, it is most effective for smokers and people suffering from respiratory diseases, assisting the body to restore health after illness, and is a pure and noble natural health product. Bird's nest has unique healing effects on moistening the lungs and strengthening the waist, strengthening the spleen and stomach, and stopping bleeding from trauma.