摘要
以纯化白魔芋精粉及其完整葡甘露聚糖粒子(KGM粒子)为对照,采用一些简便与快速测定方法对自制纯化白魔芋微粉的颗粒形貌、粒度分布及糊化特性等基本特性进行了研究。结果表明,在相差显微镜下或体视显微镜下可方便地观察、识别纯化白魔芋微粉的形貌特征:白魔芋微粉颗粒为破碎的条形或不规则微细颗粒,而相应的完整KGM粒子为扁平的椭球形或近圆球形的半透明颗粒,颗粒表面还可观察到一些加工的痕迹。激光粒度测试仪可用于快速测定白魔芋微粉的颗粒特征参数与粒度分布曲线。根据平均粒径计算推断,120～250目白魔芋微粉中1粒完整KGM粒子的平均粉碎程度达到了31～110粒微粉。快速粘度分析仪(RVA)可用于快速测定白魔芋微粉的糊化特性。测定时白魔芋微粉的适宜质量分数为1.0%,不同设置条件下均能得到典型的RVA糊化曲线。白魔芋微粉典型RVA糊化曲线的特征为:粘度随温度的变化而呈现有规律的上升(达粘度峰值)、下降(达热糊粘度)、在冷却过程中再返升(达粘度终值)的过程。
Basic properties including particle morphology, particle size distribution and pasting properties of purified micro-konjac flour from amorphophallus albus were comparatively studied with its relative konjac flour and intact KGM granules by stereomicroscope,microscope,laser particle size analyser and rapid visco analyser(RVA),respectively. The results showed that compared to the relative intact granules of konjac flour which was composed by the flattened elliptical or sphere-like translucent particles,the micro-konjac flour was comprised of strips of broken particles and irregular broken particles. There existed special marks left by colloid mill or micro mill on the micro grinded particles. Laser particle size analyser could be used as a rapid method to determine the characteristic parameter of particles and particle size distribution for the purified micro-konjac flour. The estimated degree of grinding for intact granules of konjac flour was reached that one intact particle has been grinded to 31～110 granules in 120～250 mesh of the micro-konjac flour by a calculation based on the difference between their mean particle size. Pasting properties for the micro-konjac flour could be rapidly measured with RVA. The test concentration of 1.0% for the micro-konjac flour was suitable,and all the three different instrument setup have been successfully for the testing. The typical pasting profiles for the micro-konjac flour obtained by RVA showed that the viscosity initially increase until to the peak viscosity(PV)corresponding to the initial temperature increase,then decrease until to the hot paste viscosity(HV),and then increase again until to the final viscosity(FV)corresponding to the cooling process.
出处
《中国食品学报》
EI
CAS
CSCD
2004年第4期11-16,共6页
Journal of Chinese Institute Of Food Science and Technology
