Shark's fin by color, there are yellow, white, gray, green, black, mixed and so on six kinds, including yellow, white, gray color is better. Because of the origin and baking method is not the same, there are freshwater shark's fin saltwater shark's fin. Freshwater shark's fin is dried by sunlight or impregnated with lime water, which is of better quality; saltwater shark's fin is impregnated with brine, which is of inferior quality to freshwater shark's fin.
The shark's fin can also be categorized according to the form of integrity or not. The fins that become whole after rising are called row fins, which are the best quality; the fins that spread out into a strip after rising are called loose fins, which are the second best quality. Shark fins are mainly produced in China's coastal provinces of Guangdong, Fujian, Taiwan, Zhejiang, Shandong and the South China Sea islands.
Generally speaking, the imported shark's fins are the top quality of Luzon yellow from the Philippines. The earliest people to eat shark fins are fishermen, fishermen sell sharks, the fins will be left behind for their own consumption, fish merchants found profitable, collected for the sale of goods, shark fins gradually appeared in the feast. To the middle of the Ming Dynasty, shark's fin has been widely eaten by the people, various books on shark's fin selection and cooking has been introduced.
The reason why shark fins can be eaten, because the shark's fins contain a kind of fan-shaped fin tendon, which contains about 80% of the protein, but also contains fat, sugar and other minerals, but it is difficult to be absorbed, so eat an egg absorbed nutrients than the shark fins more. Because of profiteering, people kill sharks in large quantities in order to get the precious raw material for cooking.