【摘要】 为探究冷藏(4℃)时间对馒头品质的影响,通过X射线衍射、差示扫描量热法(differential scanning calorimetry,DSC)、傅里叶红外光谱(fourier transform infrared spectrometer,FTIR)、扫描电镜(scanning electron microscope,SEM)、质构仪、pH计、感官评分等方法,从微观和宏观的角度上研究馒头淀粉粒晶体、蛋白质二级结构、微观结构、质构和感官,分析冷藏时间对馒头品质的影响。结果表明:随着馒头冻藏时间的增加,馒头的pH值呈现先降低后升高,12 h的馒头pH值显著低于0 h的馒头;冷藏12 h的馒头淀粉在2θ靠近17°和20°出现强的衍射峰,淀粉已经从无序状态向有序状态转变;随着冷藏时间的增加,熔化晶体所需的热焓值显著性增加,结晶含量也在增加;面筋蛋白二级结构中β-转角和无规则卷曲的相对含量呈现上升的趋势,α-螺旋、β-折叠呈现下降的趋势,蛋白二级结构稳定性逐渐下降;通过SEM发现,随着冷藏时间的增加,部分或全部淀粉颗粒裸露部在面筋网络外面。冷藏12 h,馒头的硬度、咀嚼性比0 h分别从2 386 g增加到17 201.367 g,咀嚼性从1 563.996增加到了4 197.586;冷藏12 h对馒头的老化有显著影响。更多还原

【Abstract】 In order to study the effect of cold storage(4 ℃)time on the quality of steamed bread,the crystal structure, protein secondary structure, microstructure, steamed bread of the starch granules from the microscopic and macroscopic perspectives by X-ray diffraction,differential scanning calorimetry(DSC),fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),texture analyzer,pH meter,sensory scores and other methods were used to study. The effects of cold storage time on the quality of steamed bread were analyzed. The results showed that the pH value of steamed bread decreased first and then increased with the increase of cold storage time. The pH value of steamed bread at 12 h was significantly lower than that of 0 h. The steamed bread starch showed strong diffraction peaks at 2θ near 17 ° and 20 °,starch has changed from disordered state to ordered state;with the increase of cold storage time,the enthalpy value required for melting crystals increased significantly and the crystal content also increases. The relative content ofβ-turn and random curl in the secondary structure of gluten protein was on the rise. The α-helix,β-folding showed a downward trend and the stability of protein secondary structure gradually decreased. After SEM,with the increase of cold storage time,part or all of the starch granules were exposed outside the gluten network.After 12 h of cold storage,the hardness and chewiness of steamed bread increased from 2 386 g to 17 201.367 g and the chewiness increased from 15 639.96 to 4 197.586. This indicated that the cold storage for 12 h had a significant effect on the aging of steamed bread.更多还原