【摘要】 本研究采用扫描电镜法、X-射线衍射法和差示扫描量热法(DSC),从淀粉的颗粒形貌特性、晶体结构特性和热力学特性的变化,来研究水分含量对燕麦淀粉糊化老化特性的影响。结果表明:燕麦淀粉的X-衍射图谱为A型,含水量较低(70%)时,老化后的燕麦淀粉凝胶质地坚硬表面空隙较大,衍射峰相对强度大,含水量较高(90%)时,凝胶表面质地均匀,衍射峰的相对强度较弱。燕麦淀粉重结晶晶体融化的起始温度(To)、顶点温度(Tp)、终止温度(Tc)和融化热焓值(ΔH),以及晶体生长速率均随含水量增加而降低,说明增加含水量可延缓燕麦淀粉老化;随着贮藏时间的延长焓值(ΔH)有所增加,说明燕麦淀粉老化度随贮藏时间延长而增加;同时,含水量在60%~90%时,燕麦淀粉重结晶的成核方式为一次成核。说明燕麦蒸煮类食品的老化度随着贮藏时间的延长而增加,但适当增加含水量可延缓贮藏过程中燕麦淀粉的老化现象。更多还原

【Abstract】 In order to investigate the influence of moisture content on the gelatinization and retrogradation properties of oat starch,the changes of oat starch characteristics in morphology,crystal structure and the thermodynamic properties by the scanning electron microscope,X-ray diffraction and differential scanning calorimetry( DSC) was studied. The result showed that the X-diffraction patterns of oat starch was A type. On condition of the lower water content( 70%) in oat starch gel,the relative diffraction intensity stronger and larger gaps were expressed. On condition of the higher water content( 90%) in starch gel,the relative diffraction intensity weaker and gel flat surface were expressed. The recrystallization transition starting temperature( To( onset),Tp( peak),Tc( conclusion)),the enthalpy( ΔH),and the crystal growth rate of oat starch re-crystallized crystals increased along with the increase of moisture content. Enthalpy increased with prolonged storage time,which showed that the retrogradation degree of oat starch being increased along with prolonged storage time. In the meantime the moisture content in 60% ~ 90%,the nucleation mode of oat starch was a nucleation. It suggested that,in the oats food processing,the retrogradation of oat foods during storage was delayed appropriately along with the increase of moisture content.更多还原