Property of food like tortilla -reinforcement of calcium and magnesium -

通过热DSC曲线、X射线衍射曲线和力学性能的测定以及SEM图像的观察，研究了碳酸钙、氢氧化钙、氯化镁和硫酸镁对糯米淀粉糊化和糯米粉面团结构的影响。添加碳酸钙后，普通大米淀粉加热DSC曲线上的吸热峰在较高温度下变宽；添加氢氧化钙后，普通大米淀粉加热DSC曲线上的吸热峰只有一个。添加氯化镁或硫酸镁可使低温下的水稻淀粉吸热峰向较高的方向移动，添加硫酸镁的水稻淀粉吸热峰起始温度向较高的方向移动。添加碳酸钙、氢氧化钙、氯化镁和硫酸镁后，加热后的糯米淀粉的X射线衍射图呈温和的玉米形曲线。含氢氧化钙的大米淀粉在氢氧化钙浓度为0.5%时贮藏模量减小，在氢氧化钙浓度为1.0%时贮藏模量增大。添加其他盐类后，非糯米饭淀粉的贮藏模量变化不大。通过扫描电镜观察，在含氢氧化钙的非糯米粉生面团中，与含碳酸钙、氯化镁和硫酸镁的面团相比，淀粉颗粒的结合得到了促进。与单纯添加氢氧化钙和氯化镁相比，添加氢氧化钙和氯化镁使加热后的糯米粉面团吸水率降低（p<0.05）。添加1.0%和1.5%的氢氧化钙可提高未加热的非糯米粉面团的破裂应力和破裂应变。加热后含氯化镁和硫酸镁的糯米粉面团破裂应力增大，含氢氧化钙的糯米粉面团破裂应力减小，但含碳酸钙的糯米粉面团破裂应力最小，含氯化镁和硫酸镁的糯米粉面团破裂应力较大。通过ESM观察，在未加热的含碳酸钙和氯化镁或硫酸镁的非糯米粉面团中，与含0.5%碳酸钙的非糯米粉面团相比，淀粉颗粒的结合得到了促进。添加碳酸钙和0.5%、1.0%氯化镁的混合物后，加热面团的吸水率较添加碳酸钙的无糯米粉面团降低（p<0.05）。氯化镁和硫酸镁的加入降低了未加热的含碳酸钙非糯米粉面团的破裂性能。添加氯化镁和硫酸镁后，加热后的含碳酸钙糯米粉面团和离子水浸泡后的含碳酸钙糯米粉面团的破裂应力和破裂能均有所提高。在含氢氧化钙的非糯米粉面团中，加入氯化镁和硫酸镁后，破裂应力增大，破裂应变减小。添加0.5%钙剂（碳酸钙或氢氧化钙）和0.25%镁剂（氯化镁和硫酸镁）的混合物，有利于非糯米粉面团的使用价值。少

The effects of calcium carbonate, calcium hydroxide, magnesium chloride and magnesium sulfate on gelatinization of nonglutinous rice starch and on the structure of nonglutinous rice flour dough were investigated by measuring the heating DSC curves, X ray diffraction and mechanical properties and by observing the SEM images. A endothermic peak in a higher temperature on heating DSC curve of nonglutinous rice starch became broad by the addition of calcium carbonate and a single endothermic peak was observed on the DSC curve of nonglutinous rice starch with calcium hydroxide. A endothermic peak of nonglutinous rice starch in a lower temperature was shifted to higher side by adding magnesium chloride or magnesium sulfate, and a starting temperature of peak in higher temperature of nonglutinous rice starch containing magnesium sulfate was shifted to higher side. X ray diffraction pattern of heated nonglutinous rice starch became a gentle corn-shaped curve by the addition of calcium carbonat … More e, calcium hydroxide, magnesium chloride and magnesium sulfate. Storage modulus of heated nonglutinous rice starch containing calcium hydroxide decreased up to concentration of 0.5% calcium hydroxide and increased at 1.0% calcium hydroxide. Storage modulus of nonglutinous rice starch did not observe the remarkable change by adding other salts.In unheated nonglutinous rice flour dough containing calcium hydroxide, the conjunction of starch particles was promoted as compared with those containing calcium carbonate, magnesium chloride and magnesium sulfate based on the observation by SEM. The water absorption of heated nonglutinous rice flour dough decreased by additions of calcium hydroxide and magnesium chloride as compared with nonglutinous rice flour dough alone (p<0.05). Rupture stress and rupture strain of unheated nonglutinous rice flour dough increased by adding 1.0% and 1.5% calcium hydroxide. Rupture stress of heated nonglutinous rice flour dough containing magnesium chloride and magnesium sulfate increased and that containing calcium hydroxide decreased, but that containing calcium carbonate was smallest and those containing magnesium chloride and magnesium sulfate were large.In unheated nonglutinous rice flour dough containing mixture of calcium carbonate and magnesium chloride or magnesium sulfate, the conjunction of starch particles was promoted as compared with those containing 0.5% calcium carbonate based on the observation by ESM. The water absorption of heated dough decreased by addition of mixture of calcium carbonate and 0.5%, 1.0% magnesium chloride as compared with nonglutinous rice flour dough containing calcium carbonate (p<0.05). The values of rupture properties of unheated nonglutinous rice flour dough containing calcium carbonate decreased by adding magnesium chloride and magnesium sulfate. Rupture stress and rupture energy of heated nonglutinous rice flour dough containing calcium carbonate and those of dough containing calcium carbonate with soaking in ionized water increased by addition of magnesium chloride and magnesium sulfate. In heated nonglutinous rice flour dough containing calcium hydroxide, rupture stress increased and rupture strain decreased by adding magnesium chloride and magnesium sulfate.The utility value of nonglutinous rice flour dough became favorable by adding mixture of 0.5% calcium agent (calcium carbonate or calcium hydroxide) and 0.25% magnesium agent (magnesium chloride and magnesium sulfate). Less