Source: China Consumer Daily
Li Jian, a professor at the School of Food and Health of Beijing Technology and Business University, said in an interview with the China Consumer Daily reporter that bird's nest is a nest built by the mixed condensation of swiftlets and a variety of swallows of the same genus with saliva and continuous feathers, which are generally 6 to 7 cm in diameter, 3 to 4 cm deep, and the weight of each bird's nest is 6 to 10 grams.
Bird's nest is mainly produced in Indonesia, Malaysia, Thailand, Vietnam, the Philippines and other Southeast Asian countries. The main production areas of bird's nest in China are Yanyan in Huaiji County, Zhaoqing City, Guangdong Province, Yanzi Cave in Jianshui County, Honghe Prefecture, Yunnan Province, and Dazhou Island in Hainan, but the output is extremely low.
Bird's nest can be sorted in a variety of ways. According to the production method, it can be divided into cave swallow and house swallow. Cave swallow refers to the nest built by swiftlets in natural caves and cliffs. House swallow refers to the nest built by the swiftlet that inhabits the bird's nest.
According to the morphology of the bird's nest before it is processed into edible bird's nest, that is, the production form, the bird's nest can be divided into grass swallow and wool swallow. Grass swallows are mainly dominated by weeds and impurities, and the outer layers and edges are connected by saliva, and most of them are processed into swallow crushed, swallow cakes and so on. The bird's nest is due to the fact that after the bird's nest is picked, it has not been processed or treated, and it is presented as a form mixed with some swallow hairs.
Bird's nest can be divided into swallow cups, swallow strips, swallow silk, bird's nest, bird's nest, bird's nest cake and bird's nest according to its shape. Bird's nest is a complete bird's nest where the wool is plucked. Bird's nests are in the process of picking, packing or transporting, many complete bird's nests are crushed to form thick strips of bird's nests. Swallow silk is packed by workers after collecting the ends of the thin strips that fall off when picking the hairs. Swallow cake is made by pressing the crushed swallow that falls off when the bird's nest is picked and kneaded with edible glue. Bird's nest is the head and tail of bird's nest glued to both sides of the swallow board. Bird's nest is a bird's nest that appears in the form of fragments and belongs to the fragments that fall off during processing.
Li Jian said that bird's nest can be divided into white swallow, yellow swallow and blood swallow according to color. Generally, the color of the bird's nest with an earlier picking time is white, which belongs to the natural white, and the white is slightly yellow, called the white swallow, also known as the official swallow; the whole bird's nest or bird's nest with a late picking time is more yellow, called the yellow swallow; the whole bird's nest color is uneven brownish red or brownish yellow, the bottom color is darker, and the middle and edges are lighter called blood swallows.
Bird's nest can also be classified according to the harvest season, the bird's nest harvested from February to April is called the first bird's nest, and the bird's nest harvested from May to October is called the second and third stage swallows.
Xi Yu, a postdoctoral fellow at the School of Public Health of Zhejiang University, said in an interview with the China Consumer Daily reporter that not all nests built by swallows are edible bird's nests, and the types of swiftlets that can be used to build edible bird's nests are Javan swiftlet, white-bellied swiftlet, burrowing swiftlet, small gray-loin swiftlet, Indian swiftlet, short-billed swiftlet and large swiftlet. In addition, the white-waisted swifts of the swift family Swift family are also available for human consumption. (Reporter Sun Yanming)