The effect of different varieties of soybean and calcium ion concentration on the quality of tofu

The Japanese food tofu (bean curd) was prepared by the traditional method using 15 varieties of soybeans. The tofu quality was evaluated on the basis of colour, taste and texture. The texture measurements were subjective and instrumental (hardness and cohesiveness).A slight variation in the texture of tofu was due to the 7S and 11S proteins in the soybean but an important factor affecting the texture of tofu was found to be the amount of calcium ions added during processing. The firmness and coarseness of the product increased with increases in the amount of calcium ions added and a linear relationship was found between the protein content of the beans and the calcium sulphate concentration required for good quality tofu.