Tofu, also known as bean curd, is a food made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is a component in East Asian and Southeast Asian cuisines. There are many different varieties of tofu, including fresh tofu and tofu that has been processed in some way. Tofu is bought or made to be soft, firm, or extra firm. Tofu has a subtle flavor and can be used in savory and sweet dishes. It is often seasoned or marinated to suit the dish. Tofu originated in Han dynasty China some 2,000 years ago. Chinese legend ascribes its invention to prince Liu An (179122BC). Tofu and its production technique were introduced into Korea and then Japan during the Nara period (710794). Some scholars believe tofu arrived in Vietnam during the 10th and 11th century. It spread into other parts of East Asia as well. This spread probably coincided with the spread of Buddhism because it is an important source of protein in the vegetarian diet of East Asian Buddhism. Li Shizhen in the Ming Dynasty described a method of making tofu in the Compendium of Materia Medica. Tofu has a low calorie count and relatively large amounts of protein. It is high in iron and depending on the coagulants used in manufacturing (e.g. calcium chloride, calcium sulfate, magnesium sulfate), it is often high in calcium and/or magnesium. The term tofu by extension can be used in similarly textured curdled dishes that do not use soy products at all, such as “almond tofu” (almond jelly), (egg), (sesame), or peanut tofu (Chinese luòhuāshēng dòufu and Okinawan ).