(1.河北农业大学 食品科技学院/河北省农产品加工工程技术研究中心, 河北 保定 071001;2.河北大学 生命科学学院, 河北 保定 071002;3.德益阳光生物技术(北京)有限公司, 北京 100085;4.承德市农林科学院, 河北 承德 067000;5.天津市场和质量监督管理委员会, 天津 300050)
(1.College of Food Science ant Technology/Engineering Technology Center for Agricultural Products Processing of Hebei Province, Hebei Agricultural University, Baoding 071001, China;2.College of Life Sciences, Hebei University, Baoding 071002, China;3.Prosit sole Biotechnology (Beijing) Co Ltd,Beijing 100085, China;4.Chengde Academy of Agriculture and Forestry Sciences, Chengde 067000, China;5.Tianjin Market and Quality Supervision Administration, Tianjin 300050, China)
The combined application of transglutaminase (TGase) and glucono-δ-lactone (GDL) in the preparation of color soft tofu was optimized by the response surface methodology. Vegetable juice was added into soymilk as natural dyes. Using the springiness and cohesiveness of color soft tofu as key response values, the response surface model about the concentration of coagulants and the temperature for soymilk coagulation were set up. The most important effect on texture of color soft tofu was the temperature of coagulation. The models were reliable and could be used to predict the springiness and cohesiveness of color soft tofu. The optimum conditions of the color soft tofu preparation were confirmed as follows:TGase concentration of 1.4g/L, GDL concentration of 1.7g/L, and the coagulation temperature for soymilk gel formation of 53℃. Verified by the sensory evaluation experiment and texture profile analysis, the color soft tofu showed better characteristics than lactone tofu in the market. This optimal conditions for color soft tofu preparation could be helpful to diversify tofu products.