西米淀粉的物化性质研究

研究了西米淀粉的组成、颗粒形貌及糊化、透明度、老化方面的性质,并与木薯和马铃薯进行了比较。结果表明,西米淀粉的蛋白质含量为0.21%,直链淀粉含量为28%,颗粒为椭圆形,西米淀粉的起糊温度为70.3℃,热糊稳定性高,凝沉性比薯类淀粉弱,西米淀粉的透明度为57.5%,比薯类淀粉易老化。为进一步了解西米淀粉的特性及应用开发提供了一定的理论依据。      

西米醋酸酯淀粉物化性质研究

利用扫描电子显微镜、聚焦光束反射测量仪,红外光谱仪和布拉班德粘度计对西米醋酸酯淀粉性质进行测定和分析,并与马铃薯醋酸酯淀粉进行比较。结果表明:马铃薯淀粉较西米淀粉更易引入乙酰基,乙酰化后淀粉颗粒形状未发生大的改变,西米原淀粉粒度分布为单峰,而马铃薯原淀粉粒度分布为双峰,前者平均粒径大于后者,乙酰化后西米淀粉和马铃薯淀粉粒径均增大;经醋酸酐酯化后西米淀粉和马铃薯淀粉起糊温度、峰值温度及峰值粘度均降低,热稳定性增加,凝沉性变弱。     

西米柠檬酸酯淀粉物化性质研究

利用扫描电子显微镜、红外光谱仪、聚焦光束反射测量仪、X射线衍射仪和布拉班德粘度计对西米柠檬酸酯淀粉性质进行测定和分析,并与西米原淀粉进行比较。结果表明,西米淀粉经柠檬酸酯化后,其表面被侵蚀,甚至有颗粒已破碎;酯化后淀粉颗粒平均粒径从30.8μm减至27.1μm;柠檬酸酰基引入会破坏淀粉颗粒结晶,淀粉相对结晶度从24.5%显著降至11.6%;通过对淀粉糊粘度分析发现,西米淀粉与柠檬酸在酯化作用下发生交联,其浆液在粘度测定过程中不发生糊化和胶凝。     

西米交联淀粉的理化性质

以三偏磷酸钠为交联剂,采用水分散法制备西米交联淀粉,利用扫描电镜、聚焦光束发射测量仪、Bra-bender快速黏度计和紫外分光光度计对其性质进行测定和分析,并与西米原淀粉进行比较。结果表明:西米交联淀粉发生了中等程度的交联;西米交联淀粉保持了西米原淀粉绝大多数颗粒完整、呈椭圆形、存在断切面和断切面处有凹坑的形貌特征,但其表面比较粗糙,有凹痕,且断切面处凹坑更加明显;西米交联淀粉颗粒粒径分布图呈单峰,在水相中的平均粒径为30.1μm,比西米原淀粉颗粒小;西米交联淀粉比西米原淀粉难于糊化,其热稳定性和冷糊稳定性均优于西米原淀粉,有很高的最终黏度;西米交联淀粉的透光率为5.1%,小于西米原淀粉,其透明度较差。     

西米淀粉颗粒结构与性质的研究

利用光学显微镜、扫描电子显微镜、X-射线衍射仪、聚焦光束发射测量仪、差式量热扫描仪和紫外分光光度计对西米淀粉的性质进行测定和分析,并与马铃薯淀粉和木薯淀粉进行比较。结果表明:西米淀粉颗粒为椭球体,颗粒表面光滑;偏光十字明显;颗粒在水相中的平均粒径为27.3μm;晶体结构为C型,结晶度为25%;DSC测得To、Tp、Tc分别为68.51、72.79、82.29℃,ΔH为12.00J/g;透明度较好。     

非晶颗粒态西米淀粉的理化性质研究

利用乙醇溶剂法制备非晶颗粒态西米淀粉,并对其理化性质进行研究。研究表明:非晶颗粒态西米淀粉具有特殊的偏光性质,中心具有同心圆形的亮环;在乙醇溶剂中进行西米淀粉颗粒的非晶化转化过程中,原有的结晶结构完全破坏,西米淀粉形成了新的结晶结构,X-衍射图谱在13、21°有2个新的衍射峰,结晶类型也由原来的A型转变为V型;由于新晶体的形成,非晶颗粒态西米淀粉的耐高温能力提高,糊的透明度由29.1%下降到4.7%。     

西米淀粉糊流变特性研究

利用Brookfield旋转粘度计研究西米淀粉糊流变性、抗剪切能力、触变性以及温度、浓度和剪切速率对表观粘度的影响,为西米淀粉在食品行业的应用提供理论上的依据。结果表明:西米淀粉糊属于非牛顿流体。温度、浓度、剪切速率对流变性质均有影响,在同一浓度和剪切速率下,表观粘度随温度的增加而减小;在同一温度和剪切速率下,表观粘度随浓度的增加而增加;在同一温度和浓度条件下,淀粉糊的表观粘度随剪切速率的增加而减小。西米淀粉糊属于剪切稀化体系,抗剪切能力优于马铃薯淀粉糊和木薯淀粉糊;淀粉糊粘度随剪切速率增大的上行线与随剪切速率减小的下行线之间存在滞后圈,说明西米淀粉糊具有触变性。     

西米羟丙基淀粉的理化性质研究

利用环氧丙烷为醚化剂制备西米羟丙基淀粉,并对其理化性质进行研究。结果表明:醚化后淀粉的颗粒形貌没有发生变化;糊化起始温度(T_o),峰值温度(T_p),终止温度(T_c)以及热焓值(ΔH)均高于原西米淀粉;透明度提高,远高于西米原淀粉;凝沉性增强,冷糊和热糊稳定性提高,表观黏度降低,流动性增加。     

西米柠檬酸酯淀粉颗粒结构与性质研究

利用光学显微镜、扫描电子显微镜、紫外分光光度计和布拉班德黏度计对西米柠檬酸酯淀粉的性质进行测定和分析,并与西米原淀粉进行比较。结果表明:西米淀粉经柠檬酸酯化作用后,其表面被侵蚀,甚至有的颗粒已破碎,偏光十字变弱,结晶度降低;西米柠檬酸酯淀粉的溶胀度和透明度都远远小于原淀粉;通过淀粉糊黏度分析发现,西米淀粉与柠檬酸在酯化作用下发生交联,其浆液在黏度测定过程中不发生糊化和胶凝。     

马铃薯淀粉的物化性质研究

研究马铃薯淀粉的组成、颗粒形貌、粒径大小及溶解度与膨润力、透明度、凝沉性、糊化方面的性质,并与绿豆、玉米淀粉进行比较.结果表明,马铃薯淀粉的蛋白质含量为0.27%, 直链淀粉含量为20.4%,颗粒为椭圆形,平均粒径为40 μm;马铃薯淀粉的溶解度与膨润力较高;马铃薯淀粉的透明度为66.8%,凝沉性高于豆类淀粉,峰值黏度为2 000 BU.     

西米辛烯基琥珀酸淀粉酯的结构表征及性质研究

采用现代仪器分析方法对西米辛烯基琥珀酸淀粉酯的结构特征、颗粒形貌、粒径分布、乳化性、糊粘度等性质进行了测定和研究,并以西米原淀粉作为参照。结果表明,西米淀粉经辛烯基琥珀酸酐处理后,产品的红外光谱在1570cm-1和1714cm-1处出现新的吸收峰,608cm-1处吸收峰加强;颗粒表面受到损害,形状发生不规则变化;颗粒粒径分布不均,平均粒径大于西米原淀粉;乳化能力和乳化稳定性有显著提高;糊粘度明显增大,热糊稳定性高,凝沉性较弱。为进一步研究西米辛烯基琥珀酸淀粉酯的开发应用提供了一定理论依据。     

西米品质特性研究

以粳米、糯米为对照,西米为试验材料,观察其淀粉颗粒形貌,并研究其食用品质、蒸煮特性、理化特性以及抗消化性.结果表明,西米淀粉颗粒为椭球体,颗粒大于粳米、糯米淀粉颗粒;粳米、糯米淀粉颗粒为多面体结构,表面较光滑;西米蒸煮品质、食味品质优于粳米和糯米;3种米粉的溶解度和膨胀度随温度的升高呈增大趋势,其中西米粉与糯米粉相差不...     

羧甲基甘薯淀粉钠的理化特性研究

通过与甘薯淀粉相比较,研究了不同取代度羧甲基甘薯淀粉钠的理化特性,包括:粘度的测定;不同温度、不同pH及电解质（NaCl）和非电解质（蔗糖）存在下的粘度曲线及冻融稳定性;颗粒形貌和X-射线分析。结果表明:羧甲基甘薯淀粉钠比天然淀粉具有较高的粘度,电解质（NaCl）和非电解质（蔗糖）的存在,影响其水溶液的粘度,羧甲基甘薯淀粉钠几乎没有凝胶性能,颗粒形貌及晶体结构与甘薯淀粉相比均发生较大变化。      

Differential scanning calorimetry: gelatinisation of sago starch in the presence of sucrose and sodium chloride

The effect of sucrose and sodium chloride (NaCl) on sago starch gelatinisation was investigated by differential scanning calorimetry (DSC). The gelatinisation of starch in the presence of low levels of water and high levels of sucrose was studied. The gelatinisation temperature was found to increase in the presence of sucrose, whereas the gelatinisation enthalpy was unaffected. The gelatinisation temperature range was not as broad in the presence of sucrose as without sucrose. Furthermore, the shape of the gelatinisation endotherm was changed by the addition of sucrose. The double endotherm obtained in limited water–starch systems was changed into a single endotherm, similar to the endotherm obtained in excess water–starch systems at higher temperature. DSC was also used to examine the effects of water and NaCl content on the phase transitions of sago starch. Samples were adjusted to starch–water weight ratios of 2:3 and 3:2 in NaCl concentrations from 1 to 5 M . The gelatinisation temperature of sago starch increased and then decreased as the NaCl concentration increased. NaCl created similar effects on the endotherms with excess water content and on the first endotherm with limited water content. © 1999 Society of Chemical Industry     

Effects of cationization on DSC thermal profiles,pasting and emulsifying properties of sago starch

Cationic sago starches were prepared using an aqueous alkaline process with different levels of cationic reagent 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride (0.01–0.10 M ), sodium hydroxide (0.03–0.86 M ) and reaction temperature (30–62 °C). The degree of substitution (DS), reaction efficiency, thermal and pasting properties of cationic sago starches were analysed. Emulsifying and fat binding properties of native sago starch, cationized sago starch and commercial chitosan were compared at two different pH values (4 and 7). Degree of substitution increased with an increase in concentration of cationic reagent or NaOH, or reaction temperature. The reaction efficiency was proportional to the concentration of NaOH and reaction temperature but inversely proportional to the cationic reagent concentration. The highest DS and reaction efficiency achieved was 0.06 and 79%, respectively. The pasting temperature and gelatinization enthalpy of cationic starch (DS 0.06) were lower compared with native sago starch. Cationization increased the peak viscosity and breakdown of the starch paste but decreased the setback. The presence of cationic groups significantly increased emulsion stability, emulsion viscosity and fat binding capacity of sago starch. However, the cationic sago starch was still inferior to chitosan, which showed the highest emulsion stability, emulsion viscosity and fat binding capacity. There was no significant difference between the surface tension values of native and cationic sago starch and chitosan. The influence of pH on emulsifying properties was not significant. The emulsion stability of the cationic sago starch improved due to an increase in viscosity and fat binding capacity but not its surface active property. Copyright © 2004 Society of Chemical Industry     

部分石栎属淀粉糊特性研究

采用偏光显微镜、分光光度计、旋转粘度计等现代分析仪器,对部分石栎属淀粉糊特性进行了较详细的研究。实验结果表明,石栎属淀粉糊具有糊化温度高、酶解率较高、透明度低、凝沉稳定性较强、冻融稳定性较差的特性。在pH值6.0～8.0范围内石栎属淀粉糊粘度较高,温度和转速对糊粘度有一定影响,浓度对糊粘度有显著影响。