冻藏时间对冷冻面团馒头品质的影响

Effect of Refrigeration Time on the Quality of Frozen Dough Steamed Bread

为探究冻藏时间对冷冻面团馒头品质的影响,本文通过采用酵母菌活性测定、馒头质构特性测定、面筋蛋白二级结构测定、扫描电镜观察等方法,从宏观和微观的角度上分析了冻藏时间的延长对冷冻面团馒头品质的影响。结果表明,随着冻藏时间的延长,酵母菌数量及存活率均呈下降趋势,其中冻藏1周后,表面和内芯的酵母菌数量均减少5.8 lg CFU/g;经过5周冻藏后,冷冻面团馒头的硬度、咀嚼性、胶着性分别增大74.6%、75.7%、75.6%;面筋蛋白二级结构中α-螺旋也随着冻藏时间的延长呈下降趋势,蛋白二级结构稳定性逐渐下降;经过扫描电镜观察发现,面筋网络结构逐步减少,淀粉颗粒与面筋结构分离,部分淀粉颗粒完全裸露。因此表明冻藏时间的延长,会导致冷冻面团馒头品质下降。本研究结果为后续提高冷冻面团馒头品质应用研究提供理论依据。

In order to study the effect of refrigeration on the quality of frozen dough steamed bread, the growth activity of yeast, the texture profile analysis of steamed bread, the secondary structure of the gluten protein and the microstructure of the dough were analyzed to find the effects of the prolongation of refrigeration on the quality of the frozen dough steamed bread. The results showed the yeast activity decreased in the frozen dough with the increase of the cold storage time. After 1 week of refrigeration, the number of yeast in the surface and inner core decreased by 5.8 lg CFU/g. After 5 weeks of frozen storage, the hardness, chewiness and adhesion of the frozen dough steamed bread increased by 74.6%, 75.7%, 75.6%. In the secondary structure of protein, the alpha helix also decreased with the prolongation of refrigeration, and the stability of secondary structure of protein decreased gradually. Scanning electron microscope（SEM） analyses indicated that the structure of gluten network decreased gradually, the starch granules and the gluten structure were separated, and some starch granules were completely exposed. Therefore, the quality of frozen dough steamed bread will be reduced with the increase of the refrigeration time. The purpose of this study aims to provide a theoretical basis for improving the quality of frozen dough steamed bread.