淀粉糊化过程的数字图像分析技术动态监测

Dynamic Monitoring of Gelatinization Process of Starch Based on Digital Image Analysis Technique

针对原有的利用偏光显微镜监测淀粉糊化的方法的不足,文中提出了一种动态监测淀粉糊化过程的新方法——累积光密度法.它利用淀粉颗粒在偏振光下的双折射光在糊化过程中逐渐减弱至消失的原理,采用数字图像分析技术对实时采集到的数字图片进行累积光密度分析,测得淀粉的糊化度.将该方法与3种传统的计算糊化度的方法进行比较发现:由于新方法能够对处于部分糊化状态的淀粉颗粒进行表征,所以测得的糊化度最高;该方法测得的淀粉颗粒糊化过程中结晶结构的消失与DSC法测得的热转变过程呈定量关系,两种方法测得的糊化度既相互区别又相互联系;新方法所得实时数据能更好地反映淀粉糊化过程中的真实情况.

In order to overcome the difficulty of the original polarizing microscope-based method in monitoring the gelatinization of starch,a new method to dynamically monitor the gelatinization process,namely the integral optical density-based method,is proposed.In this method,the gradual disappearance of the birefringence light of starch granules under polarized light is taken into consideration,and the digital image analysis technique is used to analyze the integral optical density of the acquired real-time digital image of the gelatinization,thus obtaining the gelatinization degree.Then,the proposed method is compared with three traditional methods for gelatinization degree detection.The results show that(1) the gelatinization degree detected by the proposed method is the highest due to the response of the method to partial gelatinized starch;(2) there is a quantitative relationship between the dis-appearance of starch crystal structure detected by the proposed method and the thermal change detected by DSC du-ring the gelatinization;(3) there are not only difference but also correlation between the gelatinization degrees detected by the proposed method and by the DSC;and(4) the real-time date obtained by the proposed method well reflect the real state of starch during the gelatinization.