Abstract: Yogurt was fermented from milk subjected to protein stabilization at 90 ℃ for 0 (T00), 30 (T30), and 60 s (T60) followed by sterilization at 137 ℃ for 4 s and its viscosity, texture, stability and microstructure were analyzed by a rheometer, a texture analyzer, a stability analyzer and a confocal laser scanning microscope (CLSM). The results showed no significant difference in the viscosity, stability and texture between yogurts T00 and T30. The viscosity of yogurt T60 was only 55.23%–58.98% of that of T30 and T00, and the instability index was 0.19, which was significantly higher than that of T30 and T00. In summary, as the protein stabilization time became longer, the density of yogurt proteins decreased, and protein aggregation occurred.

Key words: protein stabilization time; milk; fermentation characteristics; viscosity; texture characteristics; stability; microstructure

摘要： 将未经蛋白稳定段与经90?℃、30?s，90?℃、60?s蛋白稳定段处理的牛乳进行137?℃、4 s灭菌处理后，发酵制备酸乳（分别为T00、T30、T60组），通过流变仪、质构仪、稳定性分析仪及激光扫描共聚焦显微镜分析酸乳的黏度、质构特性、稳定性及微观结构。结果表明：T00与T30酸乳黏度、稳定性及质构特性差异不显著，T60酸乳黏度仅为T30与T00的55.23%～58.98%，不稳定指数为0.19，显著高于T30与T00酸乳。综上，随着蛋白稳定段的延长，酸乳蛋白致密度降低，蛋白呈现相互聚集现象，所制备酸乳稳定性变差、黏度降低、质地更为稀薄。

关键词: 蛋白稳定段；牛乳；发酵特性；黏度；质构特性；稳定性；微观结构