| The effects of soybean protein isolate extracted from soybean in different storage periods on Qianye tofu were examined, including hardness, elasticity and color. The results showed that the optimal storage period for soybeans used for extracting soybean protein isolate to produce Qianye tofu was 9-18 months. Compared with harvest time, the hardness of Qianye tofu produced by soybeans in the optimal storage period increased by 26.9%- 39.4%, the elasticity increased by 5.5% -7.8%, the L value decreased by 1.6%- 3.6%, and the b value increased by 5.3%-12.8%. When the soybeans stored for more than 18 months, the hardness and elasticity of Qianye tofu began to decrease, the taste was worse, the decrease of L value was not obvious, but the increase of b value was remarkable, which caused the appearance of Qianye tofu to be yellow and the selling was worse. It was also affected by the season, especially the quality of Qianye tofu produced by the soybeans stored in summer was poor. |
