A rapid freezing technique used for foods in order to retain food quality. Pioneered by American inventor Clarence Birdseye (1886–1956) in 1922, it involves a freezing process that causes the water content to freeze in a very short time, preventing the formation of ice crystals that have a destructive effect on biological cell wall structure. It is used for many foods such as fish, meat, and fruits, and is also known as quick freezing.