Tofu (Japanese: 豆腐, Hepburn: Tōfu; Korean: 두부; RR: dubu, Chinese: 豆腐; pinyin: dòufu) or bean curd is a food prepared by coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness: silken, soft, firm, and extra (or super) firm. It originated in China and has been consumed for over 2,000 years. Tofu is a traditional component of many East Asian and Southeast Asian cuisines; in modern Western cooking, it is often used as a meat substitute.
Nutritionally, tofu is low in calories, while containing a relatively large amount of protein. It is a high and reliable source of iron, and can have a high calcium or magnesium content depending on the coagulants (e.g. calcium chloride, calcium sulfate, magnesium sulfate) used in manufacturing. Cultivation of tofu, as a protein-rich food source, has one of the lowest needs for land use (1.3 m/ 1000 kcal) and emits some of the lowest amount of greenhouse gas emissions (1.6 kg CO2/ 100 g protein).