Tofu or bean curd is a food made by coagulating soy milk and then pressing the resulting curd into soft white blocks. It is of Chinese origin, and it is also a part of East Asian and Southeast Asian cuisines such as Chinese, Japanese, Korean, Indonesian, Vietnamese, and others.

History of tofu

Though soybean is not technically a grain, according to Chinese culture soybean was one of the essential grains amongst the five sacred grains including rice, wheat, barley and millet. Though soybean is not technically a grain,according to Chinese culture soybean was one of the essential grains amongst the five sacred grains including rice, wheat, barley and millet. Though soybean is not technically a grain, according to Chinese culture soybean was one of the essential grains amongst the five sacred grains including rice, wheat, barley and millet.

Tofu is made from soybeans. Soybeans are not really considered as grain because they are oilseeds. In China they are considered to be one of the five sacred grains along with rice, wheat, barley and millets (1).

Discovered over 2000 years ago by the Chinese, tofu is sometimes called “the cheese of Asia,” because of its physical resemblance to a block of farmer’s cheese. Tofu was introduced in Japan in the 8^th century, where it was known as “okabe,”. It was only in 15 th century they started calling it as tofu in Japan. While serving as a traditionally made dish, tofu did not gain its popularity in Japan until the 17th century. In Japan there are more than 30,000 exclusive tofu shops which sell different varieties of tofu.

Making of tofu

Tofu is made by adding a coagulating agent to soymilk. Many tofu makers use calcium salt as the coagulant. The curd separated is separated from the water and pressed into a block. This is tofu! About 1.5 kgs tofu can be made from 1 kg soybean or 7 litres of soymilk.

The factors that influence processing steps and quality of tofu (2)

• properties of soybean seeds
• processing scale
• soaking and heating conditions
• type and concentration of coagulant

Nutritive value of tofu

Tofu is a good source of protein (8%) and calcium (241 mg /100 gm tofu). It contains less than 2 % carbohydrate and 4.8 % fat that is free of cholesterol. Tofu also contains isoflavones which have several health beneficial properties such as antioxidant activity.

Texture of tofu

Tofu is available in various textures such as

• Extra firm
• Firm
• Soft
• Silken

Firmer tofu is made by removing more water. Larger sized soybean varieties make better quality soy milk and tofu. Soybean varieties with more protein content and less than 10 % moisture yield higher amount of tofu.

Colour of tofu

Soybeans with very little yellow or near white hilum and seed coat tend to give whiter tofu and milk. Soybeans with darker hilum and seed coat give greyish or yellowish colour tofu and milk.

Versatility of tofu

Tofu is a bland product and has porous structure which allows it to absorb the flavours of the foods it is added to. Tofu can blend well with almost any food it is added to. When it comes to what to make with tofu imagination is the limitation. It is an ideal alternative for Indian paneer and almost everything that can be made with paneer can be made with tofu.

References

1. Dey, A., Rasane, P., Kaur, S., Singh, J. and Luwang. (2017) Tofu: Technological and nutritional potential. https://www.researchgate.net/publication/323676422_Tofu_technological_and_nutritional_potential
2. Zhang, Q., Wang,C., Li,B., Li, L., Lin, D., Chen, H., Liu, Y., Li, S., Qin, W., Liu, J., Liu , W. and Yang,W. (2018) Research progress in tofu processing: From raw materials to processing conditions, Critical Reviews in Food Science and Nutrition.Vol.58(9) https://www.tandfonline.com/doi/full/10.1080/10408398.2016.1263823?scroll=top&needAccess=true